Phsy X GPU Question

[feebeeteemoff]

Hey guys, just got my GTX 660 and i noticed i can use a separate GPU for PhsyX processing, i have a spare GTX 470, would i beable to use that one for the processing? And if its possible, do i connected it and use the SLI bridge connector? or do i just plug it in and give it power.
Thanks in advance !

 

[nadim615]

I've never thrown in an extra card for PhysX, but I'm pretty sure you just throw it in and give it power (don't connect the SLI bridge). And then in the Nvidia control panel, you select that card for PhysX (it'll ask you which card you want to handle PhysX, select that card 😛)

 

[wolfram23]

You just plug it in and there should be an option in NV control panel to use a separate card as a PPU.

It's not really worth it, though. Depending on the motherboard you can lose some speed as it drops down your PCIe bandwidth. There's also only about a dozen PhysX games and most of them will run just fine on your single card with PhysX on.

 

[nadim615]

You just plug it in and there should be an option in NV control panel to use a separate card as a PPU.

It's not really worth it, though. Depending on the motherboard you can lose some speed as it drops down your PCIe bandwidth. There's also only about a dozen PhysX games and most of them will run just fine on your single card with PhysX on.

Really? I just thought it wasn't worth it due to the fact barely any games support it, and your primary (or secondary if in SLI) should be able to do it fine.. But since he says he has a spare 470 lying around, wouldn't it be worth it?

So then, how do you calculate the PCIe bandwith of your motherboard, and your GPU's?..
~ASUS Crosshair V Formula-Z
~2xGTX 660TI

 

[wolfram23]

Really? I just thought it wasn't worth it due to the fact barely any games support it, and your primary (or secondary if in SLI) should be able to do it fine.. But since he says he has a spare 470 lying around, wouldn't it be worth it?

So then, how do you calculate the PCIe bandwith of your motherboard, and your GPU's?..
~ASUS Crosshair V Formula-Z
~2xGTX 660TI

Won't really matter for you as you're running a very high end motherboard, and with 3 GPUs installed they run at 16/8/8. An 8x PCIe 3.0 is as fast as a 16x PCIe 2.0.

I'm on older hardware, before PCIe 3.0 was released. So I'm running 5850s at 8x/8x PCIe 2.0. That isn't really the issue, though.

When I plug in a 3rd card for PhysX, my 3rd PCIe slot runs through the south bridge and it bottlenecks to data stream. I've found in benchmarks like 3DMark Vantage my score goes down 2k or so just by having the 3rd card plugged in.

So, it really depends on his setup.

But like you said, PhysX will run fine on the single GPU anyway. Personally I'd rather extract some money out of the 470 or maybe put it in a media rig for some TV gaming in the living room.

 

[maxinexus]

Right now PhysX is just overrated and useless. During the gameplay you absolutely do not notice if it is on/off unless you specifically look for it...but then you are not playing the game.

 

[nadim615]

Won't really matter for you as you're running a very high end motherboard, and with 3 GPUs installed they run at 16/8/8. An 8x PCIe 3.0 is as fast as a 16x PCIe 2.0.

I'm on older hardware, before PCIe 3.0 was released. So I'm running 5850s at 8x/8x PCIe 2.0. That isn't really the issue, though.

When I plug in a 3rd card for PhysX, my 3rd PCIe slot runs through the south bridge and it bottlenecks to data stream. I've found in benchmarks like 3DMark Vantage my score goes down 2k or so just by having the 3rd card plugged in.

So, it really depends on his setup.

But like you said, PhysX will run fine on the single GPU anyway. Personally I'd rather extract some money out of the 470 or maybe put it in a media rig for some TV gaming in the living room.

I see.. But I heard somewhere (not sure if this is true) that AMD only runs PCIe 2.0 or something like that?.. But my 3DMark score isn't too bad at all, so I don't think I'm getting any bottleneck..