Funky SLI performance.

M

Moog

[H]ard|Gawd
Joined
May 22, 2002
Messages
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So I recently purchased a second 7800GT to run an SLI configuration (it's an identical card to the one I previously purchased) in the system in my sig. I got both cards to install fine, but I'm getting really funky performance in FEAR especially. The game runs smoothly, but then slows down to a slideshow. Likewise, HL2 runs mostly fine, but slows down tremendously in many spots and sometimes crashes randomly/lockups the computer. None of this happened before I got the second card.

I know both cards work fine (I tested them in each of the K8WE's slots seperately and they handled multiple rounds of BF2 without issue) and when it came to actually installing the cards in SLI, I first installed one to get the system up and running, then the second, which the system detected and asked if I wanted to enable SLI. Up to that point everything works like clockwork, but gaming performance leaves much to be desired.

Am I missing something? There aren't any BIOS settings that pertain to SLI except "SLI Aperture Setting", which I've tried adjusting to no avail (the settings are "Disable", "Master", and "Slave") and no jumpers that relate to SLI that I know of and all nforce drivers are current, the card temperatures were in the high 50-low 60 range during gameplay (nothing unusual), and nothing is overclocked at all in the system (the motherboard doesn't support OC'ing).
 
Interesting, but I've never experienced any of these problems (or those listed in that thread) until trying SLI.
 
You might want to try drivers 78.01 with that dual cpu system... I hear there were issues with the 8x.xx drivers and dual core system, so I am guessing it's possible the same could be true of dual cpu systems... also, Sir-Fragalot has a similar type of SLI setup, maybe same mobo as you... maybe he can chime in or you can PM him.
 
For what it's worth (on an Intel rig), I had no issues whatsoever, then I enabled SLi and had a hard system lock up on DOD: Souce. I think it may be the drivers - I'm using 81.98.
 
Scream And Fly said:
For what it's worth (on an Intel rig), I had no issues whatsoever, then I enabled SLi and had a hard system lock up on DOD: Souce. I think it may be the drivers - I'm using 81.98.
Click to expand...

Power related?? what PSU are you running?
 
I don't think it's power related. This is my XPS 600, so it has a 650W power supply (I think). LOL
 
Welll - this might be a bit offbeat, but I just read this article.. try powering one of the card off one of the 4 pin molex connectors with the 6pin to 4pin adapter.. see this URL for details.. . A hard lock on a nomally stable machine after enabling SLI seems power related to me.. but that's just a guess.. could be drivers. also.. but typically drivers just make games crash and stuff from my experience..
 
I dropped back to 81.85 which seemed to fix my issues. I'll post more if I run into any other problems.

Strangely, I could install 77.77 and both cards would install fine, but I couldn't enable SLI with anything below 8x.xx.
 
I'm having some problems, too.. With COD2 and FEAR. It seems like anything with softshadows gets artifacting... And my game locks up for around 10 seconds at a time. It'll be playing fine, with a high FPS then I just lock up for a while. Sometimes I gain response again, sometimes it crashes the PC.

Click the following links below for example screenshots:
* FEAR Lighting Issue/Artifacting
* COD2 Artifacts

I've got an A64 4000+, an MSI K8N Neo4 SLI-Platinum, 1GB RAM, two BFG-6800 Ultras in SLI and an Antec NeoPower 480 PSU.

Here's what I've tried so far:
  1. Using Driver Cleaner, I've nuked the Nvidia drivers and have tried - nv_fw 81.85, 81.84, 81.95 and 81.98
  2. I've disabled SLI, run it in single card mode
  3. Opened the case, swapped card slots and tried it again in SLI

The only thing that has seemed to have fixed COD2 is if I set the game in "safe mode" which is 680x480, DirectX7 and 22Khz low quality audio.

I'm beginning to wonder if it's a power issue or maybe my RAM. Any ideas?
 
PS! said:
I'm having some problems, too.. With COD2 and FEAR. It seems like anything with softshadows gets artifacting... And my game locks up for around 10 seconds at a time. It'll be playing fine, with a high FPS then I just lock up for a while. Sometimes I gain response again, sometimes it crashes the PC.

Click the following links below for example screenshots:
* FEAR Lighting Issue/Artifacting
* COD2 Artifacts

I've got an A64 4000+, an MSI K8N Neo4 SLI-Platinum, 1GB RAM, two BFG-6800 Ultras in SLI and an Antec NeoPower 480 PSU.

Here's what I've tried so far:
  1. Using Driver Cleaner, I've nuked the Nvidia drivers and have tried - nv_fw 81.85, 81.84, 81.95 and 81.98
  2. I've disabled SLI, run it in single card mode
  3. Opened the case, swapped card slots and tried it again in SLI

The only thing that has seemed to have fixed COD2 is if I set the game in "safe mode" which is 680x480, DirectX7 and 22Khz low quality audio.

I'm beginning to wonder if it's a power issue or maybe my RAM. Any ideas?
Click to expand...


It sounds like one of your cards (or both maybe) are throttling back from heating... maybe.. or could be a power issue also.. 480W PSU is marginal for two 6800 ultras... plus I know my old MSI Neo4 SLI had issues getting adequate power through the pci-e slots... I could not run my 6800GTs at ultra speeds because of the lack of power... when I moved to a DFI board, same cards and psu, they ran way higher than ultra speeds all day long.. bizarre!!

Anyways... heat and lack of power can cause the types of issues you are experiencing... it's also very possible that they can you can only see them with FEAR and CoD2 because of the demands they put on your system... what load temp do your cards get to? so maybe try down-clocking your cards to say, 6800GT speeds... 350/1000 and see if the issues persist.... if they go away, then you have to possibly open your case and stick a house fan right there, pointed at the innnards... just to really cool it off, test like that, if that does not do it... it's likely going to be a power issue... which might be hard to solve with that mobo... I have just found the MSI Neo4 sli plat to not have enough juice to run two 6800Ultras... well, mine would not, and I have read about other peeps with that issue.. pci video cards draw more power from trhe slots than they go from the external connector (unlike AGP video cards) so moving to a different psu might not fix the issue... it's a tricky situation... you might need to play those games with your cards down-clocked to like 400/1050 (which is the highest stable number I could get my 6800s to on my MSI neo4...) until you can swap in a mobo with an external power connector for extra pci-e power.. like the DFI, Asus, and some others have... the new MSI diamond plus has that also.. that's supposed to be a nice board.. anyways..

I hope it's just a heating issue tho.. check it out and let us know what you find.
 
Well, it wasn't power. I went out and bought a new SilentStone 650W PSU today. Came back, installed, played COD2 for a while and same problem.

Just finished formatting and reinstalling windows. Don't think it's a heating issue as the CPU stays around 55 and both the 6800-U's stay around 75 at high load.
 
ok - first off, I should have more overtly said "dont to run out and buy a new PSU first thing"... sorry for that, but in all likelihood you'd need a more powerful psu -very- soon anyways, so now you have one. Anyways, you should really have read my post where I said:

revenant said:
"if that does not do it... it's likely going to be a power issue... which might be hard to solve with that mobo... I have just found the MSI Neo4 sli plat to not have enough juice to run two 6800Ultras... well, mine would not, and I have read about other peeps with that issue.. pci video cards draw more power from trhe slots than they go from the external connector (unlike AGP video cards) so moving to a different psu might not fix the issue... it's a tricky situation... you might need to play those games with your cards down-clocked to like 400/1050 (which is the highest stable number I could get my 6800s to on my MSI neo4...) until you can swap in a mobo with an external power connector for extra pci-e power.. like the DFI, Asus, and some others have... the new MSI diamond plus has that also.. that's supposed to be a nice board.. anyways.."
Click to expand...

So putting a new PSU was a risky test, monitarily... if you indeed have a power issue I think it's the mobo and not the PSU... which really is a bigger hassle and sucks, but that's my hunch... now -don't- go buying a new mobo until you've run tests. try downclocking the cards and test... that should have been the first step... but I think they way I wrote that might have not been the best for itemizing the steps. gah!

Anyways... try downclocking the memory to 1050 and see if that clears the issues up.. if not, go lower down to 1000... then if that does not work lower the core, and also try some extra cooling... but you're temps seem pretty ok.. not super cool, but not critical.. yhou can try and open the case and point a fan in there.. just for testing.. if you like..
 
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