:: Back to news index ::

Dedicated PhysX GPU performance dependence on PCI-E bandwidth

with 11 comments

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 ? 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.

Written by Zogrim

November 23rd, 2009 at 10:31 am

Posted in Articles, Reviews

Tagged with ,

11 Responses to 'Dedicated PhysX GPU performance dependence on PCI-E bandwidth'

Subscribe to comments with RSS

  1. 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.



    27 Jan 10 at 9:45 am

  2. 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.



    3 Mar 10 at 8:52 am

  3. I tried a similar test using a asus p5n 570i (pci-e v1 switchable x1 or x8) and msi 750i (pci-e v2 x8) with an e5200, ATI 4830 and NV 8800gs.

    Generally speaking, my experience mirrors the article. However, the v1×1 did have noticeable, but tolerable, bandwidth issues. Both x8 slots were essentially equal however v2×8 was more fluid, I believe this is due to the halved latency of v2 and not the doubled bandwidth. Increasing the pci-e v1 bus to 111MHz reduced the lag on the v1×8 and noticeably boosted the v1×1 slot performance.

    My guestimation is that a v2×1 or better would fully satisfy any physx needs. Unfortunately, Intel chip sets typically have pci-e v1 x1 slots and even worse, they are on the south ICH bridge which introduces even more latency compared to most NV and AMD chips.



    22 Apr 10 at 11:22 am

  4. hi,
    did all tests they performed on v1 pci-e or v2, cause in article x58 chipset have both standards from different x58 and ich10 hubs? i guess it was v2 but either assume it could be v1 from south bridge too.



    5 Aug 10 at 12:36 am

  5. Am I susposed to read chinese now??

    that link goes to a chinese language website.



    2 Sep 10 at 6:50 pm

  6. jose
    Am I susposed to read chinese now??
    You don’t need to read – graphs are sayng more than enough



    3 Sep 10 at 12:46 am

  7. nobody knows? :*



    5 Sep 10 at 12:23 pm

  8. Luckily, Asus P5W64 has 4 full size PCIe slots with various lanes depending on config!!

    Nice find!!! =) (i’m sold!)



    8 Oct 10 at 8:16 pm

  9. Thanks so much, I have a Gigabyte BRIX i7 gaming system, supercompact with a GTX760 dedicated card. Can’t change card but now it seems I can take the burden of it by trying to use physic x on another 750Ti, external. I used it extensively for bitcoin mining.

    My website where you can see the design to put up to 6 cards on one mainboard with USB-cables!

    enjoy =D



    11 Dec 16 at 7:22 am

  10. There’s definately a great deal to find out about this issue.

    I really like all the points you made.


  11. Definitely imagine that which you stated. Your favourite justification appeared to be at the web the easiest thing to remember of.
    I say to you, I definitely get irked whilst other folks think about issues that
    they just do not understand about. You managed to hit the nail upon the
    highest and also outlined out the entire thing without having side-effects ,
    other people can take a signal. Will probably be back to get more.



    13 May 19 at 10:37 am

Leave a Reply

Copyright © 2009-2014. | About project | Privacy Policy
PhysX is trademark of NVIDIA Corporation