PCIe 4x how much of a bottleneck for physx "GT 240"

[ajaidev]

Now that GTX 480's benches have come and gone and i have made up my mind to get a 5870 powered rig. This means i can choose form a variety of mobo's.

Well i have selected the following possible config's for my PC:

Asrock X58 Extreme3
Intel i7 930
3GB DDR3 kit "G.Skill"
2*500GB hdd "dual RAID0 arrays"
2*5870 2GB

or

Asrock 890GX Extreme3
AMD 1055T
2*2GB DDR3 kit "OCZ"
2*500GB hdd "dual RAID0 arrays"
2*5870 2GB

Now the problem is that both X58 Extreme3 and 890GX Extreme3 have 3 PCIe slots and that means a single 4x slot is left for physx with GT 240.

In the local shop i have to pre order either of the boards before they stop the pre-orders and i cant wait too long because i have store credit that will go bad in a few days time.

Will 4x be enough for a GT 240 to compute physx... :shrug:

[Funky]

For PhysX, you should be fine.

[sniper_sung]

I don't go watercooling so I have the same idea as the OP.

My question is: do I need any hacks into the drivers (from nVidia) to enable PhysX on a crossfire setup if I add a GTX 240 into the PCIE x4 slot?

[CL3P20]

I am running Physx with a 5770+8800gs on a pb5-dlx.. 16x for primary gpu and 4x for physx gpu. I have tested with 2x->4x and noticed about a 20% gain in performance for physx..tested on my P45 @ 8x,8x I noticed another increase of ~15% from 4x->8x for physx.. I would have thought differently, seeing that even with heavy physx in game, my 8800gs was only loading ~58%. There must be advantages to latency/bandwidth thought for this increase to happen.

*i tested with FluidMark, and used AFE for monitoring GPU's.