Dedicated PhysX GPU performance dependence on PCI-E bandwidth
Using a mid- or low-end GPU as dedicated PhysX card is quite popular idea today (even among ATI owners), while PCI-E bandwidth requirements for dedicated PhysX GPU are not absolutely clear. Everyone knows, that x8 and even x4 would be enough, but what about PCI-E x1 ?
PCPOP.com has published article today, that investigates PhysX performance of GTX295 + 9800GT setup, with 9800GT used in PCI-E x1/x4/x8 cases (unnecessary pins were taped).
And, surprisingly, even PCI-E x1 usage isn’t affecting performance as much as it should at a glimpse.
You can read rest of the article here
BTW, users with old mobos (or lack of free full scale PCI-E slots) are asking sometimes – “What if I just put my old 9600GT in PCI-E x1 slot ? Would that be enough for PhysX ?“. Now they have some clarity. Of course, mechanical “adjustment” will be needed to make it fit, that can result in GPU/mobo malfunction, so we don’t recommend even to think about it until you are clearly sure.
Thanks this helped answer my question:
I have a Gigabyte extreme x58
Two 16x pcie
one 8x pcie
In order to give my 285gtx breathing room, I have my 8800gt in the bottom 8x slot.
How much of a performance hit does 8x physx have over 16x physx?
So, again thanks for the answer.
I kept it in 8x the heat generated by the two gfx cards in such close proximity isn’t worth it, especially cause I can just oc the 285 with the lower temps.
Amyn
27 Jan 10 at 9:45 am
I just bought a PCI Geforce 8400GS 512MB how bad of a performance hit would I have if I use a PCI card rather than PCI-E. My machine is an HTPC so the x1 PCI-e is being used by a TV Tuner. Any help would be appreciated.
Richard
3 Mar 10 at 8:52 am