[H] users SLi guide

revenant

[H]F Squad Captain
Joined
Apr 10, 2005
Messages
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SLI (Scalable Link Interface)

SLIzone's up-to-date SLI faq
Multi-monitor support is finally here
SLI PhysX configuration chart *

First off, if you think you have enabled SLI and just aren't sure if it's really working enable the visual indicators in the Nvidia control panel (Nvidia control panel --> Manage 3D settings --> top menu bar "3D Settings"). Once enabled, launch any 3D app (probably a game you know for sure is SLI capable) and see if you have a green bar on the left side screen (it's large and says "SLI" next to it). If you have the bar then SLI is indeed working... if you don't, check the in game settings to ensure "multi-gpu rendering" is enabled (some games have this setting and some don't). So if SLI is working fine but you are not wowed by the performance increase over single card, keep in mind SLI really shines best at high resolutions (1680x1050 and above) with image quality enhancements turned on! If you're still having issues getting SLI working properly, check out the troubleshooting steps below.


SLI troubleshooting tips

• Make sure you have up to date chipset and video drivers. X58 users can find chipset drivers here.
• Make sure you have SLI/multi-GPU enabled in the Nvidia control panel *. Typically when install video drivers they will alert you to enable SLI if the system is capable, click on the balloon alert to go right to that config area.
• Check to make sure your pci-e power connectors are on snug.** If your PSU is modular, check both ends of the pci-e power lead.
• Try re-seating the SLI bridge and/or flipping it around so it's connected the other way. (the SLI bridge is made of pcb or ribbon cable and connects the cards together from tabs on the side of the card. These come with SLI motherboards.)
• A bad driver install can cause a range of issues from bad performance to getting a permanent blank screen on windows load. Sometimes it's necessary to clean your video drivers with a driver cleaner (links below) and then re-install the latest WHQL drivers.
• Having trouble with Hybrid SLI? try SLIzone's Hybrid SLI section for specific help with that technology.

If you don't even see the option to enable SLI in the Nvidia control panel *

• Check the device manager to ensure the OS is seeing each video card and gpu (for dual gpu cards). If one seems to be missing, try re-seating the cards and/or changing their sequence on the motherboard.
• If you have a dual GPU video card and only one GPU shows up in the device manager, clean and re-install the recommended drivers that support that card. If the issue persists, you might have a bad card. Contact the mfg for further assistance.
• If you have an X58 motherboard be sure to install Forceware 180.48 or higher. SLI on X58 was a part of the Big Bang II release and will not work on a lower driver revision than 180 series.
• If you have an older motherboard, make sure you have the SLI enabled in hardware ***
• Check the bios version on the motherboard to ensure it supports SLI. (this is rarely an issue any more but might be useful to someone)

If SLI is working but you are having issues

• If SLI works for most of your games except one, you probably have to adjust or create a new profile for the game. If SLI still doesn't work after creating the profile try forcing AFR2 as an SLI rendering mode in that profile.
• Sometimes a sound card or another peripheral card might be interfering with one of the video cards or the motherboard, try pulling cards one by one (leaving the video cards) and test SLI to see if that resolves the issue.
• if SLI works but is unstable, use a validation tool (links below) to verify each card runs artifact and problem free at default clock speeds. If the cards pass individually, try them in SLI mode. If that doesn't pass you might have a cooling or power related issue.
• If you have run the validation tool and one or more of your cards are acting up and you are SURE you have good cooling plus enough power, it could be RMA time. Contact your card manufacturer for further details on getting a replacement card.
• Stability issues caused by insufficient cooling (artifacting or game crashes with a message that the display driver stopped responding) --> section "A" below.
• Stability issues caused by inadequate power (spontaneous reboots while gaming or messages about insufficient power from the drivers)--> section "B" below.
• Stability issues caused by overclocking (can be a wide range of issues from bad SLI performance to overheating to random BSOD) --> section "C" below.


* Right click on desktop --> Nvidia control panel --> Set SLI and PhysX configuration --> enable/disable SLI or enable/disable PhysX
** if applicable (some cards do not need extra power)
*** some older (650i, Nforce4 and others) motherboards have a selector card between the pci-e slots which must be installed the right direction to enable SLI in hardware, some have sets of jumpers, and some enable it with a bios setting. If you have an older motherboard be sure to check your manual for details on how to enable SLI.

Chipset and video drivers
WHQL Nvidia drivers
Beta Nvidia drivers
Intel X58 chipset drivers

Driver cleaners
XP only: Driver Cleaner 1.5 Pro
XP/Vista/Windows7: Drive Sweeper
>> The best way to ensure you get a good cleaning is to do it from safe mode. I personally do not do this every time and haven't had any issues, but it is the surest way to get a good cleaning every time.
>> Be *very* careful not to clean the wrong drivers with the driver cleaner... only clean the Nvidia display drivers!!

Performance validation tools
ATi Tool (old favorite)
OCCT Perestroïka (kind of new to the video card validation world but gaining popularity)


"A" Cooling tips

>> Keeping video cards cool during load in a multi-gpu env is very important. Overheating video cards can cause artifacting (on screen blemishes), application crahses, and in some cases full system lockups. To find out your gpu temps at load, grab a copy of eVGA Precision and leave it running in the background while you do some gaming. It will graph your gpu temps while you play. Here's a very general temperature chart for GPU load temps which spans from 6xxx --> 9xxx and GTX2xx GPUs:

b-e-s-t
40c -> 49c zone = super (if you're here you're likely water cooled or bionic air cooling)
50c -> 59c zone = great (high performance aftermarket air cooling or stock cooler with fans on high)
60c -> 69c zone = good (good target for air cooled cards with stock coolers)
70c -> 79c zone = average (probably the avg load temp for most air cooled cards with stock coolers)
80c -> 89c = warm (cards can run here fine, it's warm, but they're designed to deal with that)
90c -> and up = hot (screen artifacts and app crashing might occur at this temp depending on which card you have)
w-o-r-s-t


Because of the ever-growing variety different gpus it's hard to fit every video card's limitations into one chart. So this is meant to be a rough guide-line to give you a basic idea of what is good and what is not. The newer GTX2xxx series cards (55nm GT200b core) seem to fair better with higher temps than their older larger process cousins. People are reporting that GTX285s run in the 90c range fine, but ymmv.

>> If you are in the 90c+ temp area and think you might be having heat related stability issues, here are some things to try. Get a fan control program (eVGA Precision works well) and turn your video card fans up to 70% or higher if you can tolerate the noise. This should have an immediate impact on the gpu temps! As for case ventilation, a good general rule to follow is to get fresh air into the case from the front and/or side and then exhaust hot air from the inside out of the back and/or top. If you have a case with fan mounts in those areas, then make sure the fans in those spots are moving enough air into and out of the case to properly cool the inside. If those fans aren't moving much air make sure any dust filters are cleaned off or pull the dust filters out all together and/or get more powerful fans. Dust filters really restrict air flow and if you have an overheating issue, moving more air takes a higher priority than saving yourself on a little dust. Also mounting spot fans (like the Antec Spot Cool) to take care of hot spots that case fans can't get to is a great solution for people who don't have super ventilated cases.

>> If you are water cooling, then you are likely in the clear of most overheating issues. Still and all it's nice to have a side fan dumping air on the card pair do diminish any pooling heat between the cards. If you don't have a side fan on your case, go with an Antec Spot Cool for additional cooling help.

The was a general guide designed to cover the basics of cooling in a multi-gpu environment. If you have continued overheating issues and need help, try the overclocking and cooling forum for more help. Be sure to check that section for possible solutions before opening a new thread.

"B" Power tips

>> Getting adequate power to your video cards is vital to stable operation, especially in a multi-GPU environment. If your power supply is not capable of delivering enough power you will likely have random spontaneous reboot issues and/or general system instability at load (gaming). Sometimes the video driver will actually tell you that the card or cards are not receiving ample power. If you see this message and know you have capable power supply, make sure that the power leads to your video cards are connected and are completely dedicated to powering the video cards (if your cards require extra power). Also make sure to check your motherboard for an 'additional pci-e slot power' connector. Usually this is a standard 4pin molex connector on the mobo but some have floppy power connectors. Many SLI motherboards still have these so look carefully and make sure they are plugged in if you have one. If none of the above helps, you might have a bad PSU or your PSU is simply not capable of powering your system with both video cards installed at load.

>> Optimally it's good to get a power supply designed for a multi-GPU environment. These are very common now and have multiple pci-e power leads (6pin and/or 8pin connectors) which are designed and dedicated to powering high performance video cards. If your PSU doesn't have pci-e power leads or only has 6pin but you need some 8pin also, you might be able to get way with power adapters but only if your PSU is capable of delivering the power your card will require. Video cards usually come with these adapters, 4pin molex to 6 or 8pin pci-e and 6pin pci-e to 8pin pci-e. You can also get them from any number of e-tailors (like www.frozencpu.com and others). If you have to use the adapters be very careful you overload any of your power leads. It's best to use one power lead per card not powering anything else with that lead. Check the power supply manual to see which leads are on what rails and try to balance the system power over-all as best you can.

>> Check SLIzone's PSU planning system builders guide for specific power supply models to suit your SLI build.

This was a general guide designed to cover the basics of power in a multi-gpu environment. If you still have questions about what power supply to get or if your current one will handle an additional video card, try the power supplies forum for help. Be sure to check the section for possible solutions before opening a new thread.


Notes from users:
Avoid the Antec 550 W TruePower II EPS for an SLI system. Will not handle the load.


"C" OverClocking tips

>> Why do we overclock? well... because we can! and to get every last little bit of performance out of our hardware... This added performance should not sacrifice stability but it often will if you aren't careful. More heat, steeper power requirements (esp with more than one gpu), and running clocks higher than the hardware can support can cause a wide range of stability issues. If you are inexperienced with overclocking I would be very conservative with any overclocking you do, especially for 24/7 use. If you are planning on overclocking an SLI card pair be sure you start from a stable baseline: no stability or overheating issues and have more than enough power for your system a stock clocks.

>> WARNING: overclocking can void warranties and cause damage to components if care is not taken; do at your own risk <<
Just a *very basic* explanation of an easy way to overclock your video cards as a beginner. Grab an overclocking utility like eVGA Precision (obviously my favorite) or RivaTuner. First off, if you run your fan on AUTO still, I would switch to manual and turn it up to like 70%. Leave your core/shader clocks linked. Start overclocking by moving the core slider right (use arrow keys for better accuracy) so the frequency on the core increases by 10mhz (the shader clock will increase automatically), then hit the "test settings" button, rinse, repeat. In all honesty, I am not sure how well the "test settings" button tests the settings, but in theory it should let you know when you have gone too far. Work your way up like this until the "test settings" fails, then back your core clock off by 20mhz. Now repeat this process for the memory clocks. Once you have finished, I would use ATItool's stability test to verify your new overclock settings. This will make your cards work a bit in 3D mode while checking for artifacts and errors. Keep an eye on your temperatures during this test. If you're getting into the 90c range, turn your gpu fans up higher if you can, or back your core/shader clocks off by 10mhz... Once you think you have a stable overclock, try gaming... if you see any artifacting or have crashes, do the validation process again using your game as a test.

>> Newer drivers allows asynchronous clock operation in SLI. If you are running any 180 series or later drivers, you will notice in Precision you can choose which gpu to change the clocks on. Typically it's recommended to keep your gpu clocks the same, but if one of your cards is a bad overclocker and the other is a good overclocker, you can clock them indepedently of each other. In this case you should validate your overclock settings the same way as mentioned above, but for each gpu.


Useful links for info and downloads

More SLIzone links
Detailed SLI guides and information (some great stuff here)
Do it yourself SLI guide
SLI anti-aliasing modes
Club SLI (It's not Club Med, but hey it's free!)

HardOCP's SLI articles
Quad SLI with the mighty GTX295
HardOCP's SLI upgrade guide(OLD)
HardOCP's Nvidia SLI - Ready for mainstream? review(OLD)

Tweaking, OCing, and generally useful utilities
GPU-Z (great utility for detailed info on your gpu version, clocks, temps, and more)
eVGA Precision (light weight and very simple to use, fully SLI friendly, lets you set clocks asynchronously in SLI with new drivers)
RivaTuner (pretty involved tweaking util with a bit of a learning curve, but it's very good.)
Nvidia system tools (Nvidia app full of system monitors and overclocking utils. a bit bloated imo)

Old but good info on how SLI technology works
SLI interview with Nvidia's Chris Daniel.(VERY old but still a good read)
 
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could this thread have been started because of liitle ol me? :p

lol - by the way, thanks for your help in my other thread. :)
 
Ha - lol - no prob! :D

Honestly, there really have been a bunch of these lately... and I am getting carple tunnel typing the tips out each time. heh j/k - but we really should have a guide for SLi since it's not always the most easy of entities to get working... lots of variables.
 
A day late and a dollar short for me!! But Rev nailed it on the first guess in my case.

FYI, ABIT was completely useless and unhelpful to the point of flippancy.

[H] and BFG were the stars of the show IMO.
 
Ha! Well, not sure if it's quite [H] worthy yet... I just wrote it about 48 hours ago... been editing a bit... I think it needs a little more work... but it's getting there. :)
 
Very nice job! I would also add that when I went from a single card to SLI, I did all the above. BUT my system would not give me the "youve got SLI message"..... I just about shit. Well the first place I went was to the device manager. I forgot to load drivers for the second(newly added card) card. I thought the system would do that for me but I was wrong. Everything was peachy after I loaded the driver for card #2. I just updated to 77.77 and one load of the new drivers was recognized by both cards. I guess its a first time thing.
 
Oh - wow - good point. I added a section for checking the device manager! Thanks for the info. :)
 
updated the guide with some new content... and one DFI specific mobo tip.
 
wow revenant!! that is some seriously informative stuff there. bravo!!

i dont have SLI but if i ever do and have trouble, i know where im coming back to. :D

*sticky this please*
 
Very useful info. I got an SLI rig arriving in a few days so it's good to know the problems beforehand.

Thanks!
 
Wow thanks alot for this. I did plan on SLI in the future and this definatley cleared some things up for me. Hope it gets stickied.
 
There is good information in here, perhaps you all can work together on problems and if you find any make them known to people so they can get fixed. IMO this is worthy of a sticky, so I'll give it one.
 
Brent_Justice said:
There is good information in here, perhaps you all can work together on problems and if you find any make them known to people so they can get fixed. IMO this is worthy of a sticky, so I'll give it one.
Thanx Brent, I have been having problems with my SLI, and this has helped out."Great work revenant Thanx" :D
 
Oh hey - wow... cool. I was hoping this would get stuck :)... and yes, the idea was to have an on going thread with lots of historical and current troubleshooting tips and general information for everything SLi... I hope people will read and add to it as time goes on!
 
lee63 said:
I hope this is not to much of a stupid question but will this cooler http://www.vantecusa.com/p_fancard.html cool both cards or just the one on the bottom :confused:

This is a great addition to an SLi system... I have seen people use one or even two of them... one below pushing air up on the bottom gpu and one on top pushing air off the top of the top gpu... with an Asus mobo and one slot video cards you could get one on the bottom and one inbetween the cards even. :)

I have been using one for a long time under my card pair and have really been happy with it's performance. That combined with a nice side case fan pulling air from the outside over the card pair is just about all the "extra" cooling you really need to ensure your cards stay cool in SLi... unless you get into serious overclocking, then wate cooling or other extreme methods of cooling can come into play... but for the average user, a vantec fancard and a side case fan are a great combo! :)
 
revenant said:
This is a great addition to an SLi system... I have seen people use one or even two of them... one below pushing air up on the bottom gpu and one on top pushing air off the top of the top gpu... with an Asus mobo and one slot video cards you could get one on the bottom and one inbetween the cards even. :)

I have been using one for a long time under my card pair and have really been happy with it's performance. That combined with a nice side case fan pulling air from the outside over the card pair is just about all the "extra" cooling you really need to ensure your cards stay cool in SLi... unless you get into serious overclocking, then wate cooling or other extreme methods of cooling can come into play... but for the average user, a vantec fancard and a side case fan are a great combo! :)
Cool thanx
:D Great guide :D
 
So did Nvidia finally have SLI driver for their FX4400/3400/4500 card? If so, did anyone try it and satisfy with it?
 
Yeah - that is working I believe... but I have yet to test it personally... I just read that it worked.. those cards are essentially the same archetecture as the front line cards (GTX and GT, etc), just nicer builds (better cooling and more memory, etc) and different bioses I think... I think it's safe to say that if the card's pcb has the SLi connector than the card will work in SLi config.
 
new beta driver to support a whole slough of new features!! check it out -

http://www.guru3d.com/news.html#3075

"Sunday we posted the beta 81.26 driver, coincidentally NVNEWS posted some news regarding the series 80 drivers, pretty interesting stuff if you are a SLI user. There is more good news on the horizon for SLI owners as NVIDIA's upcoming Release 80 drivers will contain the following features and enhancements.

* TV-out / HDTV-out support for even higher resolution gaming support
* Mix and match vendors - for example, pairing an SLI supported graphics card from MSI with one from BFG or XFX
* Mix and match framebuffers (via Coolbits) - pairing a 128MB graphics card with a 256MB graphics card
* Ability to enable vsync for all Direct3D and OpenGL games
* Dynamically enable/disable SLI - rebooting is eliminated!
* Primary Display Switching
* Auto Display Detection
* Linux Support

Also, the number of SLI Optimized games will increase to around 150! This is pretty good news folks !"

get the driver here: http://downloads.guru3d.com/download.php?det=1181
 
yeah - that is a bummer, but that'll be next I am sure... I personally am extremely happy with Nvidia's level of support with getting these new features churned out as promised, and on schedule!! I think they are really "putting their money where their mouth is" and making SLi extremely flexible and very easy to use...
 
Yes, Nvidia has put together an excellent set-up and support. These 7800 GTX cards really rock!!!!
 
The mix and match framebuffer thing, does that just let you use two cards with different amounts of RAM, or does it allow for the RAM on the higher capacity card to be used fully, i.e:

256mb card + 512mb card = 256mb effective

or is it

256mb card + 512mb card = 512mb effective?

Anyone know?
 
I believe the capabilities of both cards will be lowered to those of the lowest card, to make a matched pair with the same abilities... but that is a guess.
 
Yeah - I did. I got a paster, a fan grill, a large SLi sticker/card and an SLi case badge. I put the SLi badge on my SLi bridge. I doubt I will have any use for the rest.
 
revenant said:
I believe the capabilities of both cards will be lowered to those of the lowest card, to make a matched pair with the same abilities... but that is a guess.
Now, I admit that it makes no sense to me that they could do otherwise, but I think I have read in a few places that NVIDIA has somehow allowed for the added horsepower of the better card to not be wasted.

Regarding the Club SLI stuff. I'm still waiting on my stuff! I want my case badge since my Asus one is stuck on there and I don't have an Asus board anymore!!!! :eek: :D
 
Maybe they make the more powerful card the "master" card (so to say) which does the assembly of the picture and output's that to the monitor? hmmm... Anyways, if they code their drivers well I don't see why they would not be able to use the extra horse power, as they do on the fly task managment for what each card is doing to the screen when in sfr mode. So you'd think the drivers would probe the card capabilities, then figure out roughly what percentage of the screen each card can handle, and divy the tasks appropriately... or something like that.

It took them a couple of week to deliver my shwag. heh... it's like an old car registration tag... do you pull it off or just put the new badge over it?? hmmmm... lol :D
 
I noticed something today that I had not seen before, and it could be causing issues with some folks reporting "single card performance" with SLI. I did a fresh install of windows on my gaming rig, and waited to install the video drivers until aftet SP2 was installed, which I doubt has anything to do with this, but I installed the WHQL 81.85 drivers and enabled multi-GPU support as I always do... and after some gaming, some reboots, etc.. I decided to check the default rendering mode, which was set to SFR always before, and it was on "single GPU rendering". WTF? Anyways, I know SLi was working while I was gaming, so the game configs must be overriding the driver settings there, but this could be cauing 3Dmark05 and such to report "single card like performance". The fix would be to go into the "performance and quality" and the "advanced settings" which brings up a larger list of goodies, scrol down to the bottom, and you'll see the rendering mode. Setting that to SFR is always safe, sometimes AFR is better for some games, you can play with it... also AA rendering can be fun if you're gunning with a pair of GTXs. w00t. :)
 
Yesterday I checked the load balancing thingy and the green line always seems to stay about one inch off the bottem of the screen, I thought it was ment to be in the middle so that both cards share the load :confused:
 
Well, with SFR (Split-frame Rendering) the driver analyzes the screen "content" and makes a call on what 50% of the load will entail, from a GPUs standpoint, which almost always ends up splitting the screen low, because there is usually less "data" in the uppper portions of the screen, because it's sky and walls and such.. most of the complex objects are low, on the ground, etc... That's how that anomoly was explained to me.
 
revenant said:
I noticed something today that I had not seen before, and it could be causing issues with some folks reporting "single card performance" with SLI. I did a fresh install of windows on my gaming rig, and waited to install the video drivers until aftet SP2 was installed, which I doubt has anything to do with this, but I installed the WHQL 81.85 drivers and enabled multi-GPU support as I always do... and after some gaming, some reboots, etc.. I decided to check the default rendering mode, which was set to SFR always before, and it was on "single GPU rendering". WTF? Anyways, I know SLi was working while I was gaming, so the game configs must be overriding the driver settings there, but this could be cauing 3Dmark05 and such to report "single card like performance". The fix would be to go into the "performance and quality" and the "advanced settings" which brings up a larger list of goodies, scrol down to the bottom, and you'll see the rendering mode. Setting that to SFR is always safe, sometimes AFR is better for some games, you can play with it... also AA rendering can be fun if you're gunning with a pair of GTXs. w00t. :)
This has always been the case in my experience. I think it defaults to single-card mode and depends on the game-specific profiles to override this and enable dual-card mode per game. So far, the only game I've bought that hasn't had a profile almost immediately added is Rome Total War: Barbarian Invasion. But, of course, I quickly just duplicated the original game's profile.

H
 
revenant said:
Ah -hah. I had bet 3Dmark does not use profiles either... :)
Nah! Actually, scroll all the way down, there are profiles for each 3DMark.
:p

Really, I think this is the safe way of doing things rather than try to enable some form of SLI for every game that may hate it. With games defaulting to single-card unless there is a profile added for that specific games (presumably tested by NVIDIA), there is less chance for instability and/or misconfiguration on the part of the end-user. But, of course, for those willing, you can always create a profile if you don't want to wait for NVIDIA and experiment between the different SLI modes.

Hey, speaking of SLI, I *still* don't have my Club SLI kit crap! :)
 
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