I recently upgraded my 280 GTX sli setup to two 295 GTXs. I also got a Creative X-Fi Titanium PCI-express soundcard so that my middle PCI-express slot is free. With the free middle slot, I used a 8800 GTX as a Physx accelerator.
The rest of my specs are: Q6600 at 3.2, 6gb DDR2 800 on a 680I, and a 24" monitor. I chose to upgrade my graphics subsystem because Kyle had mentioned that most games are still GPU limited. So far, I've to agree with him. My 280 GTX SLI setup was pretty nice already but even 2 280s weren't quite fast enough to allow me to turn on 8xAA or use super-sampling transparency AA at 1920x1200 in more graphically demanding games. Farcry 2 is now smooth at 1920x1200 w/8X AA + SS transparency AA w/ultra settings whereas it wasn't even playable with the same settings before.
I think I also got lucky with the two 295s that I got. My previous EVGA 280 SSCs were only capable of running at 670 (core), 1404 (shader), 2400 (ram). So far, I'm running my 295s completely stable at 670, 1458, 2450s. I think I can squeeze some more out of the shader clocks so in some ways each of my 295's GPUs is faster than the old 280s. Although the memory bandwidth and, obviously, memory capacity are still lesser than the 280s, this doesn't seem to be noticeable at 1920x1200. The only game which the lesser ram makes a difference is GTA4, where I have to use medium texture settings. I can however max out almost everything else in GTA4 and still be able to run at 30-40fps. I know for sure that my 2 280s weren't capable of doing so.
With regards to using the 8800 as a PHYSX accelerator, that might seem like overkill but it actually does bring a nice performance increase. Nvidia's drivers are still kinda dumb with PHYSX configuration so it isn't possible to use 1 GPU for Physx and 3 GPUS for SLI. One reason why I chose a 295 Quad-SLI setup over a 280 Triple-SLI setup is so that I can use the middle slot for a dedicated Physx accelerator. I'm surprised none of the major hardware sites have tried something like this yet.
The performance with a quad-sli + a 5th GPU as a physx accelerator is simply amazing. In cryostasis, I get 58fps w/max settings at 1920x1200. Without the 8800 GTX, it's about 10 fps. The same performance differences are seen in UT3 and Mirror's Edge. Without the 8800 GTX, the minimum framerate sometimes dips to 40 or high 30s, whereas the minimum is only about low 50s with a 8800 GTX.
So in conclusion, for those that have a similar CPU/Mobo or 280 GTX sli system as me, I think it's worthwhile to consider upgrading to a 5 GPU setup instead of an I7 system if games are your main concern.
I would love to see Hardocp run similar tests with their more extensive tools and measuring methods. Please make it happen, Kyle!
The rest of my specs are: Q6600 at 3.2, 6gb DDR2 800 on a 680I, and a 24" monitor. I chose to upgrade my graphics subsystem because Kyle had mentioned that most games are still GPU limited. So far, I've to agree with him. My 280 GTX SLI setup was pretty nice already but even 2 280s weren't quite fast enough to allow me to turn on 8xAA or use super-sampling transparency AA at 1920x1200 in more graphically demanding games. Farcry 2 is now smooth at 1920x1200 w/8X AA + SS transparency AA w/ultra settings whereas it wasn't even playable with the same settings before.
I think I also got lucky with the two 295s that I got. My previous EVGA 280 SSCs were only capable of running at 670 (core), 1404 (shader), 2400 (ram). So far, I'm running my 295s completely stable at 670, 1458, 2450s. I think I can squeeze some more out of the shader clocks so in some ways each of my 295's GPUs is faster than the old 280s. Although the memory bandwidth and, obviously, memory capacity are still lesser than the 280s, this doesn't seem to be noticeable at 1920x1200. The only game which the lesser ram makes a difference is GTA4, where I have to use medium texture settings. I can however max out almost everything else in GTA4 and still be able to run at 30-40fps. I know for sure that my 2 280s weren't capable of doing so.
With regards to using the 8800 as a PHYSX accelerator, that might seem like overkill but it actually does bring a nice performance increase. Nvidia's drivers are still kinda dumb with PHYSX configuration so it isn't possible to use 1 GPU for Physx and 3 GPUS for SLI. One reason why I chose a 295 Quad-SLI setup over a 280 Triple-SLI setup is so that I can use the middle slot for a dedicated Physx accelerator. I'm surprised none of the major hardware sites have tried something like this yet.
The performance with a quad-sli + a 5th GPU as a physx accelerator is simply amazing. In cryostasis, I get 58fps w/max settings at 1920x1200. Without the 8800 GTX, it's about 10 fps. The same performance differences are seen in UT3 and Mirror's Edge. Without the 8800 GTX, the minimum framerate sometimes dips to 40 or high 30s, whereas the minimum is only about low 50s with a 8800 GTX.
So in conclusion, for those that have a similar CPU/Mobo or 280 GTX sli system as me, I think it's worthwhile to consider upgrading to a 5 GPU setup instead of an I7 system if games are your main concern.
I would love to see Hardocp run similar tests with their more extensive tools and measuring methods. Please make it happen, Kyle!