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Dedicated PhysX card

Discussion in 'Graphics Cards' started by SMAndy, 29 Sep 2009.

  1. SMAndy

    Gangster

    Joined: 28 Jan 2009

    Posts: 401

    Location: Gloucestershire

    I know there are benefits to having a separate graphics card for dedicated physX processing... I have a few questions though.

    First and foremost, does a board supporting Crossfire allow for 2 nVidia cards to have one as PhysX?

    Second... What would the performance hit (if any) be like for using it on my board? I have 2 PCIe full length slots. If i use just one card, its at x16 bandwidth. If i have 2 cards in there, then they both run at x8. Do nVidia cards even work on a x8 slot? My main card is a GTX260, core 216. My secondary card if i use one will be an 8800GT.

    Would I just be better off sticking with my single GTX260 with physX enabled?

    Cheers.
     
  2. Amnesia

    Sgarrista

    Joined: 22 Jun 2007

    Posts: 8,953

    Location: Buckingham Palace

    it would probably have been quicker for u to just stick the extra card in and see if it works than think up the questions :p
     
  3. SlugForAButt

    Mobster

    Joined: 5 Sep 2009

    Posts: 2,547

    Location: God's own country

    Joined up thinking. ;)
     
  4. Princey

    Soldato

    Joined: 26 Apr 2003

    Posts: 5,608

    Location: Staffordshire

    I'm guessing that since your board is crossfire it won't work. However you can get PCI physX cards for around £30 now.
     
  5. D13

    Hitman

    Joined: 4 Oct 2008

    Posts: 983

    yes I believe that (assuming you can use at least 2 pcie lanes at x8 ech) you can use a nvidia card for physx in a non-sli board.
     
  6. SMAndy

    Gangster

    Joined: 28 Jan 2009

    Posts: 401

    Location: Gloucestershire

    Thanks Amnesia, seems having a few thousand posts doesn't guarantee you're a helpful person...

    Thanks everyone else though.

    Has anyone tried this setup on a similar board? I'm asking the question rather than just doing it because there is quite a bit of effort involved in finding the old graphics card, and then sticking it in my pc. Yes, i'll admit i'm a little lazy, but I don't want to risk corrupting drivers and things if its not supported.
     
  7. uv

    Sgarrista

    Joined: 16 May 2006

    Posts: 8,435

    Location: Manchester

    Except nVidia has dropped support for the old PhysX cards - newer games and drivers just won't use it.
     
  8. unknownsock

    Wise Guy

    Joined: 25 Mar 2009

    Posts: 1,691

    Location: Leeds, UK

    I think up to the 4890 level x8 lane will be fine for a graphics card, any higher and i think it would bottle neck?

    It depends on your chipset if it support crossfire or SLI.
     
  9. Amnesia

    Sgarrista

    Joined: 22 Jun 2007

    Posts: 8,953

    Location: Buckingham Palace

    i cant see a reason why it wouldnt work....its not like u will be trying to crossfire/sli them.

    performance hit should be very little ..possibly a couple of fps regarding the drop from 16x to 8x.

    and try the 2 card solution to see if u can get it working...post back let us know if it works



    btw dont try just the latest drivers as nvidia doesnt always play nice....try some earlier versions if ur not having any luck
     
  10. Freddie1980

    Soldato

    Joined: 25 Sep 2009

    Posts: 7,312

    Location: Billericay, UK

    If your using an ATI card and for some reason want a Geforce card to do PhysX then you may as well no bother as you only flushing you money down the drain. Nvidia have dropped PhysX support for Geforce cards that are being used in conjunction with a non Geforce video card as of driver revision 186.

    Link.
     
  11. sturmtruppe

    Hitman

    Joined: 27 Feb 2009

    Posts: 571

    Location: Hinckley

    unless you stick with old drivers which AFAIK shouldnt be an issue, anyone clarify?
     
  12. Greebo

    Caporegime

    Joined: 20 Jan 2005

    Posts: 38,607

    Location: Co Durham

    Yes the old drivers still work. Only problem is that the version the dropped the support was the version which saw massive performance gains in physx and they had finally started to get it right.
     
  13. HazardO

    Underboss

    Joined: 16 Jun 2009

    Posts: 7,623

    Location: Cambridge

    SLI support is not required to run 2 Nvidia GPUs where one is a display adapter and the other is a PhysX device.

    As far as bandwidth is concerned, your board will provide each slot with 8 lanes of PCIe2, which will be enough. (8 lanes of PCIe1 would not be). The difference in performance between 8 lanes of PCIe2 and 16 lanes of PCIe2 on current high end single GPU cards is less than 2% as far as frame rates are concerned.

    What isn't clear is just how much GPU power is needed for any current PhysX implementation in any game (My suspicion is that the answer is not much, and your GTX260 won't suffer much running it at the same time as being the primary display adapter.) However I haven't seen anyone try any decent PhysX requirements testing.
     
    Last edited: 1 Oct 2009
  14. Amnesia

    Sgarrista

    Joined: 22 Jun 2007

    Posts: 8,953

    Location: Buckingham Palace

    he is using 2 nvidia cards


    dont be too sure...not that ive tested it myself but i recall someone saying enabling physx in batman crippled the framerates so a secondary card could help...how much i have no idea but im guessing a graphics card dedicated to do that 1 job should do it damn well
     
  15. SMAndy

    Gangster

    Joined: 28 Jan 2009

    Posts: 401

    Location: Gloucestershire

    Wow, I didn't expect to have any more responses to this. Thanks for the explanations and things.

    Amnesia: Apologies for the snip, just seemed a bit like you were telling me to "go away" though in different words...

    At the moment, my 260 runs the games i have perfectly well, so the 1-2% drop because of going to 8 lanes doesn't seem too bad. I think my most demanding game at the moment is Fallout 3. Maybe a PhysX card would increase performance... maybe not. Since there's not much knowledge of this actual setup, I may save my PCI slots by not putting a graphics card to block them... I'll keep it as a possibility for future releases though, especially if i get my hands on a PhysX intensive game.

    Cheers for the input!


    I wonder if Portal utilises lots of PhysX...
     
  16. Mr Paul

    Soldato

    Joined: 19 Oct 2002

    Posts: 5,502

    Location: Reading UK

    AFAIK Portal doesn't use PhysX....
     
  17. Lightnix

    Soldato

    Joined: 11 Sep 2007

    Posts: 5,281

    Location: from the internet

    Aye, Portal's a Source engine game, it uses Havok.
     
  18. Mr Paul

    Soldato

    Joined: 19 Oct 2002

    Posts: 5,502

    Location: Reading UK

    Ah yes that's Intel and ATI ;)