Having trouble enabling Physx

[imported_Shaq]

I am trying to enable Physx in a spare 1x slot to go with my SLI 260 cards. I am using a 1x to 16x riser adapter for a 9800GT. I have also tried a 9600GT. The 9800GT/9600GT shows up in the control panel, device manager, GPU-Z and everything looks good. However when I bench the setup there is no difference at all in fps. I know the 1x slot will reduce bandwidth but there should be an increase or decrease in fps not exactly the same +/- 1-2%. The 1x slot works as I had a Ageia PPU in there and it ran significantly slower.

I have tried disabling SLI also and enabling the 9800GT and still there is no difference. The 9800GT still runs in 2D mode according to EVGA Precision on my G15. I am running all of this in windows 7 32 bit with the latest 185.85 drivers. I booted into safe mode and used driver cleaner and reinstalled drivers. I mainly am using the Cryostasis tech demo as it seems like the most taxing on hardware but I have also tried all the available Physx demos. I also have Windows XP to try this on but it is mainly used for Windows 7. Whats going on here?

 

[SunnyD]

Is there anything specifically letting you set which GPU runs PhysX? My guess is that one of your GTX260's is taking the PhysX load.

 

[lopri]

Try with a single GTX 260 and a 9800 GT? Maybe SLI is confusing the PhysX.

 

[imported_Shaq]

Yes I set the drivers to use the 9800GT as the Physx card and tried disabled SLI in the drivers and set the 9800GT as the PhysX card. I am stumped because I believe I did everything correctly. It won't even let you set a PhysX card in XP because they crippled the drivers I suppose.

I guess I will get a refund on the 9800GT and use that money to upgrade later on when DX11 cards come out. I only had 2 GB free with all those cards in my system. lol I'll get 64 bit Windows 7 too later. Thanks for your help.

 

[biostud]

is there any reason for a physX card when you have 2xGTX260 fully cabable of running physX and "no" titles supporting physX?

 

[imported_Shaq]

I like Cryostasis and it bogs down quite a bit even with 2 260's at 1600 resolution. It uses PhysX extensively and will even more when the new PhysX patch comes out. Even the particle system uses PhysX. Right now, firing the PPU machine gun cuts the frame rate in half. If I could offload the PhysX workload onto a dedicated PhysX card it might keep the frame rate consistently high.

But the point is moot as it doesn't work. I don't want to go tri-SLI or quad-SLI as it is too expensive, but a 9600GT for PhysX is only $60. There are more PhysX titles coming this year also, but 260 SLI will probably be sufficient for those.