Maher's Digital World

SLI manual, or why two nuts rockets is better then one. :)
(http://i1-news.softpedia-static.com/images/news2/Nvidia-Will-Release-a-Hybrid-SLI-Solution-2.jpg) (http://i1-news.softpedia-static.com/images/news2/Nvidia-Will-Release-a-Hybrid-SLI-Solution-2.jpg)
(http://1.bp.blogspot.com/-IFE0WC_3dXY/UXK7jZFFAVI/AAAAAAABRfA/0LV3wzMuSLI/s1600/soviet-space-program-propaganda-poster-25.jpg) (http://1.bp.blogspot.com/-IFE0WC_3dXY/UXK7jZFFAVI/AAAAAAABRfA/0LV3wzMuSLI/s1600/soviet-space-program-propaganda-poster-25.jpg)


Кomяde Humbert in other topic (http://www.nomaher.com/forum/index.php?topic=1879.msg15669#msg15669) asked some questions about NVidia SLI.
When I set up the SLI I had the same questions, and explain this is requires a more complexe answer, than just a short post. So, here is the manual about SLI.

1) What is NVidia SLI.
As we can read in corresponding page of Pediwikia (https://en.wikipedia.org/wiki/Scalable_Link_Interface), SLI is Scalable Link Interface, i.e., this is a technology to use two or more GPU to accelerate rendering of graphical operations by separating the job between them. The basic idea of SLI (it was developed before it was called SLI, and even before the NVidia came to market - you can read about this in this article (https://en.wikipedia.org/wiki/Scan-Line_Interleave)) is to separate the calculation operations between two or more videocards.
Calculating of 3D transformations, raytracing and overlaying the textures on polygons is, in fact, a large array of simple matrix operations (I mean mathematical matrixes, you can ask our кomяade Scarface what is it.) The result of this calculation is the color of the pixel on display. This operations doesn't require difficult (for machine) instructions like "if-else" or "switch" statements and can be easily parallelized. When 3D game executing on PC, such operations must be executed for each pixel of image on display.
So, the simplest solution to enhance speed of this job is insert two video cards, stupidly separate image in halves and calculate the colors of the pixels of each halves on different video card.
That is what, basically, is SLI. But, of course, in real all is more complex. ;D

2) What SLI can do and what can't, what you need to create SLI.
SLI in fact have 3 basic modes: Split Frame Rendering (SFR), Alternate Frame Rendering (AFR), and SLI Antialiasing (SLI AA). I don't talk about Hybrid SLI, because that is mode using for enchance amount of memory of integrated NVidia graphics adapter and give you almost no acceleration in 3D apps.
You can read about that modes in corresponding article in Wiki (https://en.wikipedia.org/wiki/Scalable_Link_Interface).
But - that's not all. (Here we start to dig up underwater rocks). We must not discover the world of multy-GPU solutions without talking about other (linked with SLI) technologies - NVidia PhysX and Software SLI.
What is PhysX? PhysX (https://en.wikipedia.org/wiki/PhysX) is technology for accelerating computing of physical processes simulation. I.e., if at 2001 in Max Payne we saw 10 pieces of s[beep]it, which realistic flied away from enemy after we shoot at him with shotgun, then today in Borderlands II we can saw 10000 of such pieces. That's the work of PhysX. CPU can't compute this physical process at real time, but GPU-like chip can. PhysX firstly was developed with one 3-d party company, then NVidia bought them and add this technology to their videocards.
What is Software SLI? Software SLI is a technology of creating SLI without SLI-bridge. SLI-bridge is a kind of small connector, using by NVidia SLI cards for synchronization between cards. But, without it, you can create SLI with software syncing. That's will be more slowly, because PCI-E bus and CPU in this mode must execute additional operations for synchronising the rendering stream.  Warning! Software SLI doesn't work with latest NVidia cards and drivers (it was removed at GeForce 9xxx series, as I can remember). And that's bad.

For creating hardware SLI, you require:
- SLI-ready motherboard with at least 2 PCI-Ex16 ports.
- 2 SLI-ready NVidia videocards. (Some cheap NVidia models isn't SLI-ready!) This videocards must be of same series (i.e. 770+8800 will not work!), better the same vendor (different vendors can add changes in reference design), and also better produced at almost same time (because stability of SLI highly depends on components).
- Powerfull PSU.
- SLI bridge.
(http://www.evga.com/products/images/gallery/401-MB-0033-01_XL_1.jpg) (http://www.evga.com/products/images/gallery/401-MB-0033-01_XL_1.jpg)

For creating software SLI you require:
- Motherboard with 2 PCI-Ex16 slots. (On some motherboards to secondary PCI-Ex16 slot pinned PCI-Ex8 slot, read carefully the MB manual. SLI will work even in this case, but two videocards will work at -8x speed, which is not enough for modern games).
- Old NVidia drivers (don't know where to download).
- Powerfull PSU.
- Bless of Machine God (the procedure can be glitchy and tricky). ;D

After connecting the software, you must configure the drivers - in NVidia Control Panel appers new point "SLI and PhysX configuration", where you can enable the SLI, and select, what card will be master, what will be the slave, on which of them executing PhysX and where to connect monitors.

3) Underwater rocks.
-Software SLI. In fact all NVidia restrictions around it, as I can understand, is just marketing. They want to sell new and expensive cards, so they just restrict this option by software. Bloody кapиtalиsts! :)
Also, I never could turn it enabled. I had GeForce 8800GTX 640 at PCIEx16 and GeForce 210 at PCIEx8, and all I can achieve is 8800 ad main adapter and 210 as PhysX accelerator. Yes, even that was very good and adds to games new and very beauty physics. (Maybe it's the goal for some experimentations. If you want, at Christmas Holydays someone of you can try to start up mythical SoftSLI).
-In true hardware SLI you must connect monitors to master card. Secondary card works as a "thug". You are not need second monitor, you can connect only one.
- PhysX acceleration can be enabled on both cards of SLI. But I prefer to separate this.
-SLI mode (i.e., SFR, AFR, AA) configuring in NVidia Control Panel.
-Not all games work with SLI correct. For example, FarCry works with SLI but can't understand PhysX, my favorite SpaceMarine with SFR or AFR SLI works slower than without, and other my favorite ArmA2 give on SLI significant FPS but glitches with shadows.

Comrade Humbert, now, answering your questions:

Quote3) If all you have is 1 monitor, do you just connect it to either card or what?

You should connect it to a card you select as Master at NVidia Control Panel

Quote2) I know both cards must be NVidia, but do they have to be the same model? For example, can you pair 1 GTX-760 with a GTX-660, or must they both be the same?

They must be the same. GTX 760+ GTX 660 will not work at hardware SLI. You can use one of them as PhysX accelerator, but any of them is too powerful for this. Using one of them only for accelerating physics will be unwise and impractical from economical point of view.

Quote1) To get the cards to run that way, is it a simple matter of connecting the SLI bridge, or is there more to it than that?

After connecting hardware you should configure SLI at Nvidia Control Panel (Enable SLI, select what card will be the master, select what card will be the PhysX accelerator).

So, that's what I know about SLI. Post your qusetions.

Merry Christmas, we will burry you. Nya! ;D
(http://fc06.deviantart.net/fs71/f/2014/176/6/2/union_soviet_socialists_anime__221526_by_sugarundspice-d7nya3b.jpg) (http://fc06.deviantart.net/fs71/f/2014/176/6/2/union_soviet_socialists_anime__221526_by_sugarundspice-d7nya3b.jpg)

You should've mentioned that SLI requires every PCI-E x16 slot to run ATLEAST at x8 mode. You can't SLI 2(or more) cards if you've got even one of the PCI-E's running at x4. AMD CrossFire doesn't have that restriction.

Now there's one thing I don't agree with, and that's the reason why you can't hardware SLI low-end and high-end GPUs, like you want to do with an 8800GTX and a GT210. NVIDIA's marketing is else where. If you think about it, SLI is just multiple GPUs working in parallel. Now, working in parallel means they would all have to work at the same speed. How exactly is a GT210 supposed to keep up with 8800GTX? The point of SLI is scaling the performance of multiple graphics cards, and not just buying random GPUs and putting them together. The slowest one would bottleneck the rest. Even if you want to use a weaker GPU as a PhysX card, you're still bottlenecking the main GPU which would've otherwise done all the calculations, let's say, twice as fast even on it's own.

Cheers.

Quote from: shhnedo on December 25, 2014, 01:35 AM
You should've mentioned that SLI requires every PCI-E x16 slot to run ATLEAST at x8 mode. You can't SLI 2(or more) cards if you've got even one of the PCI-E's running at x4. AMD CrossFire doesn't have that restriction.

Yes, that's correct.

Quote from: shhnedo on December 25, 2014, 01:35 AM
Now there's one thing I don't agree with, and that's the reason why you can't hardware SLI low-end and high-end GPUs, like you want to do with an 8800GTX and a GT210. NVIDIA's marketing is else where. If you think about it, SLI is just multiple GPUs working in parallel. Now, working in parallel means they would all have to work at the same speed. How exactly is a GT210 supposed to keep up with 8800GTX? The point of SLI is scaling the performance of multiple graphics cards, and not just buying random GPUs and putting them together. The slowest one would bottleneck the rest. Even if you want to use a weaker GPU as a PhysX card, you're still bottlenecking the main GPU which would've otherwise done all the calculations, let's say, twice as fast even on it's own.

Cheers.

No-o, comrade, you're wrong. AFAIK, no matter what speed have videocard - task is parralleled by software (on driver level) and data transferred from RAM to GPU by PCI-E bus. I.e., this isn't "mechanical" synchronization.
(For example, in UT3, if we turn on the SLI indicator, we can see that second card is loaded for about 10-15%, and that load changing dynamically).

Quote(For example, in UT3, if we turn on the SLI indicator, we can see that second card is loaded for about 10-15%, and that load changing dynamically).

That depends on the SLI scaling for the particular game. Some games have no support for SLI, others have bad scaling(between 60% and 70%). And in 100% of the cases 3-way and 4-way SLI have the worst scaling, so those are out of the question.
My point was different. You don't pair the weakest with the strongest when it comes to building a decent PC, let alone using multiple GPUs. The option best supported by current and older games is 2-way SLI(or CF). I'm not gonna talk about 3/4-way, I already said why. The option of using a dedicated PhysX GPU is very tricky and it depends on the GPUs and the games you're playing. First, throwing in a low-end GPU WILL bottleneck the main one, regardless of the load. Keep in mind we're talking about scenarios like running FarCry 4 on a GTX780. The way around it is buying a good enough GPU that can both proccess PhysX AND keep up with the "780"(our example). If you buy a 730 for that purpose, that would just be money-spent-wrong.
Second, setting up complicated setups like this requires the right drivers(as you already mentioned) and a whole crap-ton of patience(for any set-backs). Something most end-users aren't willing to search for.
http://youtu.be/cbww3dhzK0M
http://youtu.be/PQu55bciMt4
Both of these videos prove a point.

@Daniil & Shhnedo - thanks so very much for the tutorial. I saved the entire page as a file so I can read it calmly. Now let me go specifically to my situation.

1) My hardware is OK, it's an Asus M5A99X-EVO-R2 (AMD FX-8350 processor). It supports SLI and has the 2 necessary PCIE-16 slots which run at x8 if 2 cards are installed. My card is a GTX-660 - all drivers and NVidia control panel fully installed. Oh, and my PSU is 720W modular.

2) I'm thinking of doing this because my favorite game (Diablo III) tends to hesitate slightly during extreme battle scenes when all characters are moving, explosions are going off and fires are everywhere. The game supports PhysX (I have it enabled, both in NVidia and in the game) and things fly around like in real life. When not in very heavy fighting it runs OK. I have max background FPS set to 60, foreground 150.

Now, suppose I go out and buy another GTX-660. First I hook it up and attach the SLI bridge. After booting up, select one card (the one with the monitor) as master and the other as slave. What I'm not too clear about is what SLI mode I should use. Also, should I enable PhysX on both cards or what?

Please let me know and thanks again.

BTW - went to Google translate for the inscription below Lenin's picture, and it says "Lenin's name" or "with name Lenin". Can you clarify this for me?

Quote from: humbert on December 25, 2014, 04:02 AM
2) I'm thinking of doing this because my favorite game (Diablo III) tends to hesitate slightly during extreme battle scenes when all characters are moving, explosions are going off and fires are everywhere. The game supports PhysX (I have it enabled, both in NVidia and in the game) and things fly around like in real life. When not in very heavy fighting it runs OK. I have max background FPS set to 60, foreground 150.

Now, suppose I go out and buy another GTX-660. First I hook it up and attach the SLI bridge. After booting up, select one card (the one with the monitor) as master and the other as slave. What I'm not too clear about is what SLI mode I should use. Also, should I enable PhysX on both cards or what?

First of all, you should remove the foreground fps limit. It's kinda pointless imo. :)
Second, there are mainly two options(viable ones) on the market:
- use a single more powerful GPU(GTX680/670/780(Ti)/770/980/970. You are guaranteed to get the best performance for the money... somewhat. You're paying more but you'll avoid potential problems like bad SLI optimization or lack of SLI support.
- use two mid-range GPUS(GTX660Ti/760/960(upcoming)). More often than not, two of these are cheaper than a single flagship GPU and COULD deliver similar, if not better, performance. All you have to hope for is best-as-possible SLI scaling and support. When doing this, you should atleast research the titles you want to run and check out the driver release notes. You'll probably want to update the drivers more frequently than usual.
Most PC specialists recommend going with the first option, especially now that the 980 and 970 exist. They are monstrous overclockers, consume an insanely small amout of power for the performance and are easily affordable, the best bang-for-the-buck being the 970. Now it all depends on the end-user. If you're willing to spend the time and effort in maintaining an SLI setup, go for it. If not, just try to get  more powerful GPU and sell your current one. Your choice.

Quote from: humbert on December 25, 2014, 04:02 AMBTW - went to Google translate for the inscription below Lenin's picture, and it says "Lenin's name" or "with name Lenin". Can you clarify this for me?

The person in the picture is called Vladimir Lenin (http://en.wikipedia.org/wiki/Vladimir_Lenin)(Lenin is just an alias, his real name is shown in the wiki page). The thing google translates as "with name Lenin" is something like "glory to Lenin". For some russians he's an important politician. Ofcours, everyone has his/her favourite politician.

@humbert

Quote from: humbert on December 25, 2014, 04:02 AM
1) My hardware is OK, it's an Asus M5A99X-EVO-R2 (AMD FX-8350 processor). It supports SLI and has the 2 necessary PCIE-16 slots which run at x8 if 2 cards are installed. My card is a GTX-660 - all drivers and NVidia control panel fully installed. Oh, and my PSU is 720W modular.

2) I'm thinking of doing this because my favorite game (Diablo III) tends to hesitate slightly during extreme battle scenes when all characters are moving, explosions are going off and fires are everywhere. The game supports PhysX (I have it enabled, both in NVidia and in the game) and things fly around like in real life. When not in very heavy fighting it runs OK. I have max background FPS set to 60, foreground 150.

Now, suppose I go out and buy another GTX-660. First I hook it up and attach the SLI bridge. After booting up, select one card (the one with the monitor) as master and the other as slave. What I'm not too clear about is what SLI mode I should use. Also, should I enable PhysX on both cards or what?

Please let me know and thanks again.

All is simple. In menu go to "Set up SLI, Surround and PhysX", there
-set option "SLI enable" (Or it can be named "Maximize performance with SLI") (marked as 1)
-and switch PhysX to "auto-select" (marked as 2).
(Don't forget - connect the monitor to a card plugged in first PCI-Ex16 slot. It will be selected as "master" card automatically.)
(http://i61.tinypic.com/65sahe.jpg) (http://i61.tinypic.com/65sahe.jpg)
Then, go to "3D Performance management", there go to second tab ("Program settings" or such), find Diablo in list of your programs, and set
in "SLI rendering mode" - "Execurte althernative rendering 2" (marked as 3)
in "Power management mode" - "Prefer maximal performance" (marked as 4)
(http://i59.tinypic.com/jphe93.jpg) (http://i59.tinypic.com/jphe93.jpg)
(reverse translation may be not quite correct, sorry, I have only translated russian drivers),
That's all. You shouldn't change anything in game.

Quote from: humbert on December 25, 2014, 04:02 AM
BTW - went to Google translate for the inscription below Lenin's picture, and it says "Lenin's name" or "with name Lenin". Can you clarify this for me?

The best translation is pathosly "For the Lenin!" (or "Bless with Lenin's name"). In soviet traditions this phrase was something between pray and war cry, with pathos level "over 9000" (Just like the SLI technology is advertised by NVidia ;D ;) ).  Pathos view of poster and two rockets I select to show the overpower of SLI solutions. It's a kind of humour. :)

@sshnedo
You are partially wrong, comrade. Today SLI support provide by game means almost nothing. Because modern NVidia drivers have the force mode, which forcefully turn on SLI in any 3D apps. (But that is glitchy mode because in that case, for example, Mozilla Firefox will flickering - it also try to use some 3D resources).
Usage of weak GPU as PhysX asselerator will bottlenecked in scenario "FarCry 4 on 780+210", yes. But not for reasons you said, but because of amount of PhysX operations in FarCry 4 and PCI-E bus performance. "Cheap GPU for PhysX acceleration" for FarCry4 means something like at least GF 650.
Also, read the manuals and litherature about PC design. Sometimes you post nonsence.

And... You don't understand jokes. :( ;D

@sshnedo
Also me and you forgot to add one important thing about PhysX.
PhysX enchance the physical effects, but it doesn't enchance the graphics performance. Increasing FPS like in videos you posted is because additional PhysX card take part of calculations from GPU and CPU.
But, graphics adapter working as pure graphics accelerator (not PhysX) must be powerfull enough to render all particles added by PhysX acceleration. In a limit, we can get a situation when PhysX starts to decrease performance - when graphics adapter unable to render all objects, calculated by PhysX.

This topic obviously requires verbal communication. I'm sure we'd better understand eachother if we could talk in person. I'll stop right here.

Quote from: Daniil on December 25, 2014, 10:15 AM
"Cheap GPU for PhysX acceleration" for FarCry4 means something like at least GF 650.

Atleast we're on the same page here.
Also, I'm no hardware specialist with "20+" years of experience behind my back, but I can asure you I know enough about PC components to build any type of PC for any budget. We're discussing multi gpu configurations, not the whole system. ;]

P.S. I like the comrade thing. Makes me feel like a russian again. :)

Quote from: shhnedo on December 25, 2014, 03:04 PM
This topic obviously requires verbal communication. I'm sure we'd better understand eachother if we could talk in person. I'll stop right here.

Quote from: Daniil on December 25, 2014, 10:15 AM
"Cheap GPU for PhysX acceleration" for FarCry4 means something like at least GF 650.

Atleast we're on the same page here.
Also, I'm no hardware specialist with "20+" years of experience behind my back, but I can asure you I know enough about PC components to build any type of PC for any budget. We're discussing multi gpu configurations, not the whole system. ;]

Maybe you're correct, honourable shhnedo. We can dispute about this until hell melted, and even in this case we will stay each with his own opinion about a problem. Multi-gpu and performance is very complex topic, so it's better to make an experiments and achieve new levels of performance, than uselessly dispute, showing each other our ignorance.

QuoteP.S. I like the comrade thing. Makes me feel like a russian again. :)

Are you ever been in our country?

Quote from: Daniil on December 25, 2014, 03:34 PM
Are you ever been in our country?

Конечно. Я родился в России. )
Though I'll have to speak English in here. You know, forum rules and stuff. )

@Daniil & Shhnedo - thank you so very much for your advice. I saved your instructions. I'm under the impression that, taking my budget into account, the best way is to attach another GTX-660 and hook them up in SLI. The next size up would be a GTX-760 which is about $20-$30 more, beyond that exceeds my financial capabilities. Based on what I've been reading, it seems 2 660's in SLI will deliver better performance than a single 760, plus the setup won't be all that difficult.

@Daniil - you mentioned that getting 2 cards from the same manufacturer (Asus, Gigabyte, etc..) is the better way. I'd have to check my records to see who made my current card - all I know is I'm using drivers and software downloaded directly from NVidia's web site. Do you believe I'm going to have a major problem if the 2 cards came from different manufacturers.

@shhnedo - it's OK to post something in a language other than English assuming you attach a translation. In your case just one line won't really make much of a difference. BTW, Google translated that as "of course, I was born in Russia". Do you live in Russia too?

Quote from: humbert on December 25, 2014, 07:55 PM
Based on what I've been reading, it seems 2 660's in SLI will deliver better performance than a single 760, plus the setup won't be all that difficult.

Considering your budget, yes. Two GTX660 would deliver better performance than a single GTX760.

Quote from: humbert on December 25, 2014, 07:55 PM
@Daniil - you mentioned that getting 2 cards from the same manufacturer (Asus, Gigabyte, etc..) is the better way. I'd have to check my records to see who made my current card - all I know is I'm using drivers and software downloaded directly from NVidia's web site. Do you believe I'm going to have a major problem if the 2 cards came from different manufacturers.

He is absolutely right about the manufacturer thing. It's best to have two identical cards.
It won't be that difficult to identify yours. Here are some tools you'll find useful:
GPU-Z (http://www.techpowerup.com/gpuz/) - specifically for monitoring your graphics card(s), it also displays detailed information about each GPU your system has
CPU-Z (http://www.cpuid.com/softwares/cpu-z.html) - sort of an AIO tool for detailed info about your CPU/motherboard/memory/graphics cards, but bare in mind that it doesn't detect GPUs very well
These were the free tools. You could consider buying/pirating AIDA64 (http://www.aida64.com/)(the all new and improved EVEREST). It shows the smallest details about EVERYTHING in your PC, even software(dlls and such). It also has a Sensor option which monitors temperatures and voltages, two very important things when it comes to SLI or OCing. I recommend the Business Edition.

Quote from: humbert on December 25, 2014, 07:55 PM
@shhnedo - it's OK to post something in a language other than English assuming you attach a translation. In your case just one line won't really make much of a difference. BTW, Google translated that as "of course, I was born in Russia". Do you live in Russia too?

Google translates correctly. I was born there but my parents decided to live in Bulgaria, soo... BOOM! 3 freaking languages in my head. And it's funny when I start mixing them up for no reason. xD

Quote from: humbert on December 25, 2014, 07:55 PM
@Daniil - you mentioned that getting 2 cards from the same manufacturer (Asus, Gigabyte, etc..) is the better way. I'd have to check my records to see who made my current card - all I know is I'm using drivers and software downloaded directly from NVidia's web site. Do you believe I'm going to have a major problem if the 2 cards came from different manufacturers.

Probably yes. Different vendors use a bit different elementary base (for example, different memory chips) and it can cause glitches.

The simpliest way to find the manufacturer of your card - open the case, plug out the card and watch on it. At most cases you'll see big brand label on cooler system of a card - something like ASUS, MSI, XFX, Zotac or such. Like this:
(http://www.overclockers.ru/images/lab/2012/10/10/1/17_1_big.jpg) (http://www.overclockers.ru/images/lab/2012/10/10/1/17_1_big.jpg)
Then, on the back side of a card (side with cooler is "front" side) very often you can find a small white or pink stiker with bar code and kind of char code, for example something like ASUS NVG8800GTX. Like this:
(http://www.overclockers.ru/images/lab/2012/10/10/1/18_1_big.jpg) (http://www.overclockers.ru/images/lab/2012/10/10/1/18_1_big.jpg)

Or if you don't want (or can't) open your PC case, you can use software recommended by shhnedo, he advise absolutely correct.

@shhnedo
ПривеÑ,! Рад слышаÑ,ÑŒ браÑ,а-славянина!
Of course, we'll follow the forum rules, кomяade. BTW, Bulgaria is very beautiful country, one of the best spa in Eastern Europe! :) Also, one my schoolmate today living in Bulgaria, in Varna (she's a translator in one company).

(http://data3.whicdn.com/images/7523206/large.jpg)

I just happened to be studying at a university in Varna. You'd think the world is bigger than this! xD
Yes, Bulgaria is a beautiful country, but if it didn't have so many retarded politicians, it would've been even better.

By the way, @humbert, we forgot to mention one of the most important parts of multi gpu configs - DA POWAH SUPPLY! I mean, @Daniil did mention it but he hasn't gone into detail. Make sure you have two of each connector the GTX660 requires, and be sure to check the label on the PSU block itself, it should have a table on it saying how many amps each rail delivers. Also, I strongly recommend having a PSU with a single powerful +12V rail. A friend of mine already had some headaches with a multi-12V rail PSU. He wasn't very lucky and had to bury one of his 560Ti's.
You'll really need a serious block since you're also running an FX-8350 chip.

Thanks for the advice on SLI. I went into NVidia's web site and it says that cards of the same model number (or at least the same GPU) will work. Also, both cards must have the same type and same amount of memory. Also, the web site clearly says 2 similar cards made by different manufacturers will work. Similarly, if one card is overclocked by the manufacturer and the other isn't, it will work too. Armed with this information, I bought an SLI compatible Asus card, 2 GB. The original one is Gigabyte. I did this because I saved myself $40 in the process, not to mention that Nvidia insists this setup will work. Fortunately, Newegg (the vendor) is very reasonable - I can always return it if there's a problem.

Oh, my PSU is 720W modular, which should be enough. I bought it last year when I bought my first GTX-660. Why? When I was playing my game and all these movements and explosions started happening, BANG! the computer shuts down completely! This has not happened since changing out the PSU. And, since I'm not planning to overlock this thing, I see no need for more fans or other coolers.

I'll tell you more when I receive it.

Quote from: humbert on December 27, 2014, 03:22 AM
will work.  will work

Nobody said they won't. It's just MORE LIKELY for them to work if they're the same brand. :) Anyway, people mostly buy identical cards when they go shoping for both of them, not when they have one and are searching for a second piece.
If the PSU manufacturer went through the trouble of making it modular, I suppose it's a decent one and has atleast 600W of actual power output, so I wouldn't worry about it too much.

After a long wait I finally received all my SLI stuff. The 2nd card arrived a week ago but didn't include an SLI connector, so I had to run out and buy one.

This is 2 GTX-660's, one is Asus and the other Gigabyte. It works great! After booting up and waiting a second, it pretty much configured itself. All I had to do was enable SLI. Diablo III is much improved. Everything moves with much more fluidity. I see semi-transparent smoke coming out of thing that are on fire (not visible before), bigger and more rats crawling around, and no slowdown or freezes during intense battle scenes. I'm not seeing overheating or any other problem.

If you're a gamer and have an SLI compatible mobo, I definitely recommend SLI.

SLI can render more textures & everything that is why you seeing additional elements in game.

Quote from: Vasudev on January 10, 2015, 12:58 PM
SLI can render more textures & everything that is why you seeing additional elements in game.

Very true! Another thing that impressed me was one scene where the character is standing in front of a waterfall. Not only does the water fall like real water, but there's also a semi-transparent rainbow where the water is falling. The rainbow is faint and looks exactly as it would in real life. Without SLI you don't see it at all.

Also, when I put both cards in, my case fan died! Here I am running 2 graphic cards at full tilt and no fan! Finally today I went out and bought 2 fans. I didn't buy more because they wouldn't fit in my case. Good thing last year when I upgraded the PSU, I got 720W modular.

add another 10-15W for case fans instead of 800W modular psu.

Quote from: Vasudev on January 13, 2015, 09:48 AM
add another 10-15W for case fans instead of 800W modular psu.

The 720W PSU was already there, I installed it when I bought the first GTX-660 because the previous one didn't have enough power and kept crashing during games. When I installed the 2nd card I went out and bought the largest fans I could install, i.e., a 92mm fan in the back and an 80mm fan on the side.

When I'm not playing a game, the air coming out of the fans is just slightly higher than room temperature. It's much hotter when you're playing, a little like the heater in my room.

@Humbert
Glad that your SLI works fine. :)
As about overheating - it's the same as with my pc case. :) I have a troubles with heat removal since my previous PC. I live in a small room, 12m², so even a dual Xeon heated it up well. Now AMD with 2 GTX-770 raise the temp for 3-5 degrees C up with easy. That's great at winter - when you came back from work, turn PC on, play a shooter for about an hour, and you can wear only underwear and T-shirt. But at summer that's a trouble.

I set up 2 fans (92 and 120 mm) on intake, and two 120 mm out on back (one 120 mm plus 120 mm PSU fan also works as out). They (and big cooler on CPU) allows keep the temp less than 65 under load.

Also, you can monitor the temperature of CPU and GPUs with SpeedFan (http://www.almico.com/speedfan.php).

Humbert there's a new card coming this Feb. based on maxwell called nvidia gtx 965. You could SLI cards for heavy price & buy 970 or 965 with lesser power consumption.

@Daniil - 12m² is no room for anything. Where is your bath and shower, and where is do you prepare food? Where you you put your heavy winter jackets and other clothes?

How big is your case that you were able to fit 92mm and 120mm fans on it? Did you cut holes or what?

You mentioned it's better in winter than in summer. That makes no sense. Obviously your place has heating or you'd freeze to death, which means the temp inside should be somewhere around 20°C. Even in summer I believe you said once A/C was unnecessary.

Speedfan won't read my fan speeds except for the CPU fan. I had to use the PSU's Molex connectors to power them. They didn't work when plugged into my mobo because its fan power has 4 pins and all fans I looked at had only 3 pin connectors. Fortunately they did have Molex power inputs, which I had to use. At least the temp does work.

This case can contain 3x120mm fans  See Here (http://www.coolermaster.com/case/full-tower/haf-932/)

Quote from: humbert on January 16, 2015, 04:18 AM
@Daniil - 12m² is no room for anything. Where is your bath and shower, and where is do you prepare food? Where you you put your heavy winter jackets and other clothes?

You mentioned it's better in winter than in summer. That makes no sense. Obviously your place has heating or you'd freeze to death, which means the temp inside should be somewhere around 20°C. Even in summer I believe you said once A/C was unnecessary.

12m² is only my own room (where I sleep, study or so, and where my computers stand). I said, now I live with parents in a flat, so we have 3 bedrooms (each about 12 m2, one my and two other for parents), main room (kind of a living room, about 20m2) and also there is other rooms (kitchen, bathroom, storeroom).
Well, it's heating, but not enough. ;D In Russia most part of heating is centralized, and all heating systems is old. So they doesn't work well. I mean, in heavy frost temp in a room is about +15, that's good but not comfortable. Troubles at summer is troubles only of my room. Our flat on 3-rd floor, and my room is close to slope of a roof. At summer roof heating on direct sunlight, and at night it starts to emit heat to air, specifically, to air near the ceiling of my room. Hot air circulation stopping, and room doesn't cooling well. (Sometimes I had hang a fan under ceiling, directed down to the door. It throwing hot air out of the room and cold air from other rooms comes to it place, cooling the room).

Of Course all of this does not go to any comparison with tropical heat in Texas, when temp of cpu under load is lower than temp of environment air. ;D

Quote from: humbert on January 16, 2015, 04:18 AM
How big is your case that you were able to fit 92mm and 120mm fans on it? Did you cut holes or what?

Speedfan won't read my fan speeds except for the CPU fan. I had to use the PSU's Molex connectors to power them. They didn't work when plugged into my mobo because its fan power has 4 pins and all fans I looked at had only 3 pin connectors. Fortunately they did have Molex power inputs, which I had to use. At least the temp does work.

I have Intel SC5275E (http://www.amazon.com/SC5275-E-Pedestal-Chassis-System-Cabinet/dp/B0002TUY1O) case, it's full-tower case, so it have places for 92mm and 120mm from the factory.

Did you try? 3-pin fans connects to 4 pins without troubles (ofcourse you must connect it follow the plastic key on connector).

Here in my house I too have central heat and, just like with you, it doesn't circulate evenly. I solved that problem buy buying small electric heaters with a fan. I just move them around from place to place as needed. In summer the same situation exists. That's why I have standing fans that I move from one room to the next as needed. Can you do the same?

During summer can you open a window in your room to allow the heat to escape?

BTW, here in Texas the summer heat isn't tropical - it's desert heat which is hotter. Miami does have topical heat - the temperature on the thermometer is less but the humidity will kill you.

With my case fans I tried what you suggested before installing the Molex connectors and the fans did not come on. In fact there's even a slot on the connector to make sure you install it right. Even like that it didn't work. Only after installing it on Molex did it work. This is something I don't fully understand - why would Asus make a motherboard whose fan connectors aren't compatible with most of what's out there? I found no case fan with 4 pin connectors.

Quote from: humbert on January 17, 2015, 06:04 AM
Here in my house I too have central heat and, just like with you, it doesn't circulate evenly. I solved that problem buy buying small electric heaters with a fan. I just move them around from place to place as needed. In summer the same situation exists. That's why I have standing fans that I move from one room to the next as needed. Can you do the same?

During summer can you open a window in your room to allow the heat to escape?

Yes, I can and do. We have standing fans in each living room, in summer it's the only salvation. :) As about windows - yes, we can, but we prefer don't do this. It's old city center - narrow streets, lot of cars, smog, CO₂ well, you understand.

Quote from: humbert on January 17, 2015, 06:04 AM
With my case fans I tried what you suggested before installing the Molex connectors and the fans did not come on. In fact there's even a slot on the connector to make sure you install it right. Even like that it didn't work. Only after installing it on Molex did it work. This is something I don't fully understand - why would Asus make a motherboard whose fan connectors aren't compatible with most of what's out there? I found no case fan with 4 pin connectors.

It's strange. I saw many ASUS motherboards (they are wide-spreaded here, 3/4 of my friends have ASUS mb-s in their PCs), and never faced such problems. We just plugging 3-pin connectors of fans to 4-pin and they started.  Maybe your case fan connectors are turned off in BIOS?

Quote from: Daniil on February 02, 2015, 11:12 AM
It's strange. I saw many ASUS motherboards (they are wide-spreaded here, 3/4 of my friends have ASUS mb-s in their PCs), and never faced such problems. We just plugging 3-pin connectors of fans to 4-pin and they started.  Maybe your case fan connectors are turned off in BIOS?

I think I'm doing something wrong somewhere, so let me explain what I did:

(1) My conclusion that it didn't work is based on connecting the fans to the motherboard pins, turning the board on and the fans not doing anything. I'm now thinking they kick in when the motherboard heats up. True? I should mention the socket on the fans has a slot to prevent an incorrect connection.

(2) My motherboard settings for Chassis Fans are:
Chassis Q-Fan Control                 ---   Enabled
Chassis Fan Speed, Low Limit     ---   600 RPM
Chassis Fan Profile                      ---  Standard

Am I doing something wrong? Other than this my board works perfectly

Humbert-> You can turn up settings for a little aggressive setting in chassis fan profile.

Quote from: humbert on February 03, 2015, 03:45 AM
I think I'm doing something wrong somewhere, so let me explain what I did:

(1) My conclusion that it didn't work is based on connecting the fans to the motherboard pins, turning the board on and the fans not doing anything. I'm now thinking they kick in when the motherboard heats up. True? I should mention the socket on the fans has a slot to prevent an incorrect connection.

(2) My motherboard settings for Chassis Fans are:
Chassis Q-Fan Control                 ---   Enabled
Chassis Fan Speed, Low Limit     ---   600 RPM
Chassis Fan Profile                      ---  Standard

Am I doing something wrong? Other than this my board works perfectly

1) - possibly true. Modern "smart" motherboards sometimes are "too smart".
2) - first, try to turn off Q-Fan. It can braking the fans if motherboard is not hot enough.
Second, Vasudev said truth - try to raise low limit of fans, up to 800 rpm.

Quote from: Daniil on February 03, 2015, 11:08 PM
1) - possibly true. Modern "smart" motherboards sometimes are "too smart".
2) - first, try to turn off Q-Fan. It can braking the fans if motherboard is not hot enough.
Second, Vasudev said truth - try to raise low limit of fans, up to 800 rpm.

I looked at the mobo's manual and, based on your advice, I think these might be better settings:

CPU Fan Control                      --  Enabled
CPU Fan Speed Low Limit        --  600 RPM
CPU Fan Profile                        --  Turbo

Notes:
(1) "CPU Fan Speed Low Limit" means the board will warn you if the fans are spinning slower than 600 RPM. This is the highest supported speed. The other option is "ignore" which essentially disables this protection.
(2) "Turbo" means "set to achieve maximum chassis fan speed". Other options are Standard (Fan speed automatically adjusts to chassis temperature), Silent (minimize fan speeds to control noise), and "Manual" (assign detailed fan speed control parameters).

Please tell me if you agree so I can open up my case and make the changes.

Quote from: humbert on February 04, 2015, 03:46 AM

Quote from: Daniil on February 03, 2015, 11:08 PM
1) - possibly true. Modern "smart" motherboards sometimes are "too smart".
2) - first, try to turn off Q-Fan. It can braking the fans if motherboard is not hot enough.
Second, Vasudev said truth - try to raise low limit of fans, up to 800 rpm.

I looked at the mobo's manual and, based on your advice, I think these might be better settings:

CPU Fan Control                      --  Enabled
CPU Fan Speed Low Limit        --  600 RPM
CPU Fan Profile                        --  Turbo

Notes:
(1) "CPU Fan Speed Low Limit" means the board will warn you if the fans are spinning slower than 600 RPM. This is the highest supported speed. The other option is "ignore" which essentially disables this protection.
(2) "Turbo" means "set to achieve maximum chassis fan speed". Other options are Standard (Fan speed automatically adjusts to chassis temperature), Silent (minimize fan speeds to control noise), and "Manual" (assign detailed fan speed control parameters).

Mr. Humbert, are you sure in what you talking about? We talked about chassis fans, and here you asking me about CPU fan. You want to tune your CPU cooler as well, or what? (Beware, don't  occasionally overheat your PC's CPU!)

If you meant chassis fans - yes, keeping in mind data from manual, 600 RPM is optimal, change profile to "Turbo" is good idea, but I think, you also should turn off Q-Fan.

Quote from: Daniil on February 05, 2015, 01:50 PM
Mr. Humbert, are you sure in what you talking about? We talked about chassis fans, and here you asking me about CPU fan. You want to tune your CPU cooler as well, or what? (Beware, don't  occasionally overheat your PC's CPU!)
If you meant chassis fans - yes, keeping in mind data from manual, 600 RPM is optimal, change profile to "Turbo" is good idea, but I think, you also should turn off Q-Fan.

Absolutely right. I simply copied and pasted the wrong one.  :(  There are identical settings for Chassis Fans. I will follow your advice and let's see what happens. Many thanks.

Humbert-> Have you noticed the tagline of nvida it says : The way it's meant to be played. Well, mobo's manual played with you :)

Quote from: Vasudev on February 06, 2015, 11:24 AM
Humbert-> Have you noticed the tagline of nvida it says : The way it's meant to be played. Well, mobo's manual played with you :)

What tagline?

As for the case fans, using Turbo mode didn't work either, so for now I've got them connected to the Molex connector. They work OK, the only problem is they can't be monitored with apps such as Speedfan. Asus tech support keeps insisting only 4-pin fans will work. I have yet to find any.

Did you try using Asus's system  monitoring suite called AI suite.