[H] users SLi guide

It should work, maybe a driver issue in your case? How do you know it's not working? Also, different apps seem to have different implementations of it.. Like the FEAR engine's vsync is SUCH a performance killer.. I pretty much can't use it.. but any doom3 engine based game it seems to work very well and doesn't hit the performance too hard... any 8x.xx series driver should allow vsync to at least work... what drivers are you using?
 
I'm using the latest ones, 91.31. I just look for the load bar and the only games that seem to work are the Doom3 based ones. Oblivion, FEAR, COD2, NFSMW,Condemned criminal origins, Painkiller, Farcry will not work in SLI with Vsync. Why doesn't anyone warn people of this bug?
 
Hmmmmmmm.... it seems to work for me fine... I'll have to run some more sanity tests to make sure though.. it's been a while..
 
rodman said:
I'm using the latest ones, 91.31. I just look for the load bar and the only games that seem to work are the Doom3 based ones. Oblivion, FEAR, COD2, NFSMW,Condemned criminal origins, Painkiller, Farcry will not work in SLI with Vsync. Why doesn't anyone warn people of this bug?
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The load balanceing bar in DirectX games is disabled when you enable vsync, but still works in opengl based games. SLi does work with vsync enabled. Ran a quick test, I normally run 1600x1200@110Hz but set my refresh rate to 85Hz for the test.

Single GPU Vsync Off Single GPU Vsync On


Muti GPU SLi Vsync Off Muti GPU SLi Vsync On
 
Yeah - FEAR's implementation of vsync is sort of bad, imo.. I had trouble using it.. seemed to make things really stuttery and such... while on the other hand I love the doom3 engine's vsync.. works perfect with very little performance hit. Hrm... maybe it's an opengl vs. direct 3d thang?? could be..
 
I understand this thread is about sli but since we are on the subject, would any of you know if ATI crossfire have the same vsync issues?
 
It's all good.. I am not sure really.. is there a problem? vsync works in SLI with openGL and direct3d apps, but the load balancing line is gone on D3D apps.. but SLI and vsync are still working. I think the performance hit in FEAR is something related to the way FEAR's engine works... The Jupiter EX engine?

As far as crossfire goes, I will say I have not heard anyone complain about vsync issues.. but I have not chatted with my buddies who have those in a while.. I think it really depends on the app's/engine's implementation of vsync.
 
Glad it helped! I keep thinking I should over-haul the OP and make a new one.. but not enough time now.. maybe later. I am trying to keep it relatively up to date, though. :)
 
I have a thread about this but think i will get better results here..

Ok, specs first..

DFI ULTRA D- converted to SLI
2x 7800GT (evga 517 is you must know)
dualcore opterown
Enermax 600watt
yadda yadda yadda

Ok, I have been useing my roommates 7800GT while he has been away. Pairing it with mine for SLI. I have a secound card of my own comming in the mail fomr the FS/FT. SLI was working great on my ultra D converted to SLI. But when he came back and I game him his card I now have a problem. My singal video 7800GT will only post in the bottom slot. I have swaped the jumpers on my board back to non-SLI. The BIOS says the ports are 2x 16x 1x 2x like they should when not in SLI but my videocard is in the 2x spop and will not work in the 16x slot. CPUz says my GPU is runnin 2x with a max of 16x...

im lost I have tried everything...
 
ok - very strange... so his card works fine in pci-e slot0 (the one closest to the cpu) but yours will not?
 
Is there a program that will show me BOTH of my cards temps in the task bar? I checked it in the nvidia software/driver settings and one was 55 and the other was 71. I have no clue why there is such a big difference. They are 7600gt's, what would cause this large difference in the temps?
 
The top card (physically) will always run a bit warmer than the bottom card due to thermal dynamics. heat pools up between the cards and it rises, so it's good to get some air movement between the cards... like with a logisys edge 3d fan bracket and have a fan pointint right at the side of the card pair, so the top part of the bottom card is getting the brunt of the air flow.. or /something/ like that.. but you don't appear to be in the danger zone yet.. 70s are still ok.. but that's not cool per say..
 
techie81 said:
Is there a program that will show me BOTH of my cards temps in the task bar? I checked it in the nvidia software/driver settings and one was 55 and the other was 71. I have no clue why there is such a big difference. They are 7600gt's, what would cause this large difference in the temps?
Click to expand...

Not in the task bar, but, Nforce monitor tool shows both card temps at once.. also MotherBoard Monitor 5 does that after some tweaking... I like mbm5 but it's sort of a chore to get it working with both cards.. you have to do a lot of reading and download the right patch to get it working with SLI..
 
So, let's say we have two of the upcoming 8800GTX cards.

And we have a power supply that is rated for Quad-SLI according to SLIZone. For argument's sake, I'm considering the ThermalTake ToughPower 750W. It has four 12v rails.

The 8800GTX has two PCI-E Power connectors on it. . . each. For a total of four.

So, obviously, we'll need an adapter to convert two standard molex 4-pin power connectors to PCI-E power connectors.

Now, power supplies, voltages, amps, and all that other stuff is sorta greek to me. But, how do I make sure that I put each adapter on its own 12v rail? (don't want them to draw from the rail already dedicated to the existing PCI-E line, or draw from each other).

Dumb question?

H
 
Not dumb.. it's not obvious.. and on quad rail psus using 4pin molex to 6pin pci-e adapters, I am not sure you'll be able to tell which rail your on with all PSUs, depending on thoroughness of documentation and/or physical labeling on the psu.. you might want to consider a psu which has rail bonding tech, so the peripheral lines end up on one big 12v rail with like 40 or 50amps.. that seems to have worked out the best for many a power hungry crossfire setup.. or wait for psus which have 4x pci-e power plugs all on different rails... native support for SLI on the G80 basically.. that or get splitters and do a lot of testing until you find the right lines to feed the card's plugs with power without issues..
 
man, for some reason all this time i thought haivng technology like sli should support dual monitors by now. seems like they basically want you to get 2 cards for gaming and a third to run your 2d stuff on. that is bonkers!

so if you are currently running sli, can you run dual monitors in 2d only or not at all?
 
revenant said:
Not dumb.. it's not obvious.. and on quad rail psus using 4pin molex to 6pin pci-e adapters, I am not sure you'll be able to tell which rail your on with all PSUs, depending on thoroughness of documentation and/or physical labeling on the psu.. you might want to consider a psu which has rail bonding tech, so the peripheral lines end up on one big 12v rail with like 40 or 50amps.. that seems to have worked out the best for many a power hungry crossfire setup.. or wait for psus which have 4x pci-e power plugs all on different rails... native support for SLI on the G80 basically.. that or get splitters and do a lot of testing until you find the right lines to feed the card's plugs with power without issues..
Click to expand...

the enermax PSU i have has diffrent colow lines down the sides of the yellow 12v lines to show what rails each line is being drawn from
 
ok - I bet other psu's have something like that also to ID the rails.. cool call on that tho. I was not aware of that.. :)
 
Anyone hear about the Antec True Power 2, 550W? Is it able to handle two 7900 GS OC cards?
 
Hi - I *think* that would work fine. I have actually been meaning to see if anyone had gone this route for more power for their 8800GTX SLI setup.. One of those little psu's should easily handle one of the 8800GTX cards, so you main psu can drive the pc and the other card. So, being that I have not played with one myself or know anyone who has, I can't say for sure it works great, but it certainly looks like it will to me.

hope that helps!
 
revenant said:
Hi - I *think* that would work fine. I have actually been meaning to see if anyone had gone this route for more power for their 8800GTX SLI setup.. One of those little psu's should easily handle one of the 8800GTX cards, so you main psu can drive the pc and the other card. So, being that I have not played with one myself or know anyone who has, I can't say for sure it works great, but it certainly looks like it will to me.

hope that helps!
Click to expand...

thx for the response revenant..

yes, I think same too, What is the consumition or amp of the 8800gtx???? this power say have 300watt with 20~25 amp in rail 12v (2 pin connector sli) if the 8800gtx dont need more, I think work perfect, I read some reviews and only said, need psu 450, amp in rail 12v with single 8800gtx..

NOTE: http://www.guru3d.com/article/Videocards/391/9/
 
are you sure you set SLI Broadcast apature to disable instead of auto? ive read nearly everywhere else it should be enabled.
 
revenant said:
Hi - I *think* that would work fine. I have actually been meaning to see if anyone had gone this route for more power for their 8800GTX SLI setup.. One of those little psu's should easily handle one of the 8800GTX cards, so you main psu can drive the pc and the other card. So, being that I have not played with one myself or know anyone who has, I can't say for sure it works great, but it certainly looks like it will to me.

hope that helps!
Click to expand...

thx for all again rev, I prefer going sure i buy this:

http://www.thermaltakeusa.com/product/Power/ToughPower/W0131/w0131.asp
 
andersondiaz said:
interesting...look here:

http://www.newegg.com/Product/CustratingReview.asp?item=N82E16817104019
Click to expand...

Oh- wow good digging! looks like it's a mixed bag, 50/50. I guess some of them are built better than others.. I would avoid it in that case.. you don't want to tempt fate with power!

on the PSU, see this: http://www.newegg.com/Product/CustratingReview.asp?item=N82E16817153043 looks like it might stress under load.

you might want to try this one instead: http://www.newegg.com/Product/Product.asp?Item=N82E16817171017 the customer reviews look more promising! :D

or PCP&P makes a nice 750W "quad" (4x 6pin pci-e power leads) which is supposed to work with 8800GTXs in SLI just fine..
 
revenant said:
Oh- wow good digging! looks like it's a mixed bag, 50/50. I guess some of them are built better than others.. I would avoid it in that case.. you don't want to tempt fate with power!

on the PSU, see this: http://www.newegg.com/Product/CustratingReview.asp?item=N82E16817153043 looks like it might stress under load.

you might want to try this one instead: http://www.newegg.com/Product/Product.asp?Item=N82E16817171017 the customer reviews look more promising! :D

or PCP&P makes a nice 750W "quad" (4x 6pin pci-e power leads) which is supposed to work with 8800GTXs in SLI just fine..
Click to expand...
its late :( ..I'm hope work fine, I love my OZC
 
ok, well, I'll keep my fingers crossed for you.. hope the one you get does the job! :)
 
that's about as good as it gets... very good PSU.. but also very big.. make sure you have the room for it. :)
 
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