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View Full Version : Worse performance with SLI....kinda.


Rayman1968
07-06-06, 03:00 PM
Specs in sig.

If I have SLI enabled and I run the video stress test in Counter-Strike: Source, the lowest fps I see is 33. This is at the point right after the test starts and you go down the shaft and then go by the spinning plates. At these plates I'll go as low as 33 fps. At places where I'm looking at nothing I'll hit almost 300 fps. This is at 1600 x 1200, 4xAA, 8xAF, all other settings at their highest, vsync off, color correction and HDR off.

If I disable SLI and run the test with all the same settings, my lowest fps (again, at those spinning plates) is around 50. But my highest fps will only be around 120 as opposed to 300.

The score with SLI is 107 fps, without SLI it's 96 fps.

So my question is.....why do I hit a 'lower low' with SLI than I do without it? I'm using the 84.21 WHQL drivers, but I've noticed this with previous versions as well.

OWA
07-06-06, 03:07 PM
Try setting the Half-Life 2 profile to AFR2. Be sure to backup the nvapps.xml file (c:\windows\system32) first and you'll also need to remove the predefined tag next to the SLI value by editing the file.

With older drivers, this helped my performance a lot. Without doing it, I was getting around the same performance with a single card. For me anyway, the counter-strike profile wasn't really being used anyway. It was going off the Half-Life2 one. I ended up just deleting the counter-strike profile and using the HL2 one and I also changed the HL2 value from whatever predefined value it was to AFR2. Both (HL2 and CS:S) seemed to run really well that way.

With the 9x.xx drivers, nothing seems to work for me. I get single card performance no matter what I do. I don't know if it's because of a CS update or because of the drivers.

Rayman1968
07-06-06, 03:36 PM
Ok, changing what you suggested really gave the frames a kick in the ass. Now my lowest in the VST is around 62 and the score went from 107 to 136.

BUT....I now have this strange 'keyboard lag' while in-game. It takes a second for my movement keys to respond. Any idea whats causing that?

Rayman1968
07-06-06, 03:53 PM
Ok, I only get the keyboard lag if I create a server right after running the stress test. If I just jump straight into the game it's fine.

Thanks for the help!

Rayman1968
07-06-06, 05:37 PM
Be sure to backup the nvapps.xml file (c:\windows\system32) first and you'll also need to remove the predefined tag next to the SLI value by editing the file.

How do I edit this file? And what exactly is it I'm editing?

The change I made to AFR2 doesn't seem to stick.

OWA
07-06-06, 08:14 PM
Just use wordpad to edit c:\windows\system32\nvapps.xml. Find the profile you want to change and then find the SLI value line. It'll probably have a predefined tag next to it. Remove that and then when you change the value from the control panel, it should stick. I suggested backing up the file in case you want to restore the original SLI value later on. You're essentially going to be replacing the SLI value Nvidia predefined with just the standard AFR2 value. I'm not sure why they have a custom value since the AFR2 value seemed to work better for me anyway.