DX11 or CUDA?

Discussion in 'Mac Pro' started by VanneDC, Feb 6, 2011.

  1. VanneDC macrumors 6502a

    VanneDC

    Joined:
    Jun 5, 2010
    Location:
    Dubai, UAE
    #1
    Hi, no doubt i am in the market for buying a new vid card for my MP.

    I will be using it for general duties as a daily driver and will also be doing lots of Photoshop/lightroom/sketchbook pro/ and also a spot of mudbox, while also dabbeling in some gaming on OSX and Win7 (fps, and rpgs)

    With Photoshop and lightroom, obviously colour and clearity of pixels quality are most important.

    now 2 cards i am looking at, are the Ati 5770 and the Nvidia GTX 285.

    I am leaning towards the GTX285, as then i will leave my current 8800GT in there to act as a physx processor, and as i need to be able to run 3 screens i cannot realy get away from having 2 cards in there.

    Also, from benchmarks I have seen, the gtx285 comes out on top in pure performance over the 5770, but it does draw more power. Also, i know the 285 doesnt do direct x 11, but it does do CUDA.

    Also i will be running the wacom cintiq driver, anyone aware of any driver issues with the GTX285... i am also leaning towards the 285 as i can get it for lots cheaper than the 5770. I dont want to go the flash n hack route anymore as i did with my old macpro 1,1 and the 4890 i had in there as system updating is a bloody nightmare and i need this mac pro for work.

    I havent owned a proper Nvidia card since my Sli 7900gtx setup years back, and was pretty happy with that back then... Though in the years between i have owned many Ati cards. I still own the 4870X2 in my PeeCee box. (though sounds like a freaking wind tunnel when under load)

    Also, lateron, can i add another gtx285 also Sli them? (for in Win 7?)

    At any rate, i am looking for advise on which card to buy... I cant stretch the budget for the 5870 as thats just to far away (cash wise) and i cant be bothered flashing one, in case apple put something in thier updates that stops the flashed card from working.

    anyways, noise and picture quality is what i need to know...

    cheers and thanks in advance...:apple:
     
  2. goMac macrumors 603

    Joined:
    Apr 15, 2004
    #2
    You don't have any software that uses CUDA, so DX11.

    CUDA is going to be replaced by OpenCL anyway.
     
  3. Erasmus macrumors 68030

    Erasmus

    Joined:
    Jun 22, 2006
    Location:
    Hiding from Omnius in Australia
    #3
    It's true. OpenCL will replace CUDA soonish, and isn't tied to a particular GPU manufacturer. You should check if the 5770 supports OpenCL (I assume it does, as it's quite new).

    However, DX 11 is just another gaming API, and both cards will run games. If the 285 GTX is faster and cheaper, then I vote you forget CUDA, OpenCL and DX 11, and go for the 285.
     
  4. Mikey7c8 macrumors regular

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    Sep 15, 2009
    Location:
    Montreal, Canada
    #4
    GTX 285, bc dual cards in one system all doing output.

    You *can* get it working with different GPU vendors but in my experience it can be a pain in the arse.
     
  5. dimme macrumors 65816

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    Feb 14, 2007
    Location:
    SF, CA
    #5
    Are you sure you can run the 285 and the 8800gt. I think the 285 reqiures both power connectors.
     
  6. goMac macrumors 603

    Joined:
    Apr 15, 2004
    #6
    Can't run dual GTX 285s without a lot of power hacking in the Mac Pro. You can run dual 5770s however.

    And this, you can't run both a 285 and an 8800 in a Mac Pro, again, without significantly hacking the power.
     
  7. VanneDC thread starter macrumors 6502a

    VanneDC

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    Jun 5, 2010
    Location:
    Dubai, UAE
    #7
    what do you mean by hacking the power?

    iam sure it aint too hard to grab a molex to pcie 6pin adaptor from the second optical drive bay.... or am i missing something?
     
  8. goMac macrumors 603

    Joined:
    Apr 15, 2004
    #8
    That'll get you enough power to run a 285 and an 8800, but not two 285s.

    (And that's assuming your second optical bay is open.)
     
  9. VanneDC thread starter macrumors 6502a

    VanneDC

    Joined:
    Jun 5, 2010
    Location:
    Dubai, UAE
    #9
    ahh, i get you, i thought you were referring to running only the 285 and 8800gt.. my bad.. :)

    that said though, will i see any benefit of leaving the 8800GT in there with the 285? or should i remove it.. (that is of course if i get the 285)

    yeah at this stage, iam only looking at a single 285 with the 8800gt or i guess solo on the 5770...

    will the extra 512mb of the 8800gt help me out anywhere? (sides the fact iam going to need its dvi plug anyways to run my 3rd monitor...

    also i am rather confused a little as i have been checking benchmarks in windows a bit as well ref the 285 and the 5770... seems the 5770 is even out gunned by the 4870 and 4890 in a lot of places... what gives?

    if that is the case, then i think my choice is made and will be getting the 285...

    as long as no one knows any issues with the 285 with the wacom drivers...

    cheers
     
  10. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #10
    There's an easier way to get additional power than hacking around with the MP's internal connectors, so long as you can spare an optical bay and a PCI bracket to run the power cord through, unless you want to modify the back of the case (prevent's the potential of damaging both the PSU and logic board by not trying to draw more power than they can handle over the specific rail and PCB traces it's being drawn from/over). Cleaner than running a separate PSU outside of the case as well.

    ePOWER EP-450CD 450W ATX12V / EPS12V Modular Power Supply. At $20USD, it's cheap too ($26 w/ shipping). ;)
     
  11. goMac macrumors 603

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    Apr 15, 2004
    #11
    Let me put it this way... You have an 8 core machine. Do you REALLY need a physics co-processor? I'm sure you'll have a core or two spare that can handle the load. :)
     
  12. karsten macrumors 6502a

    karsten

    Joined:
    Sep 3, 2010
    #12
    he probably wants to play metro 2033. physx helps a ton on that. i'm running it on a 5770 with the original gt120 doing physx on a mp 2009:)
     
  13. goMac macrumors 603

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    Apr 15, 2004
    #13
    Again, do you really think one of his 2.8 ghz cores wouldn't be faster running Physx than his GPU? :)
     
  14. karsten macrumors 6502a

    karsten

    Joined:
    Sep 3, 2010
    #14
    physx is more optimized for the gaming calculations tho probably hard to say. i'd say pick up a cheap 120 and put in there and try it then you're not out much:D
     
  15. goMac macrumors 603

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    Apr 15, 2004
    #15
    You keep saying Physx but Physx runs just fine on CPU. It doesn't require a GPU. :)

    I used to have a GPU acting as a Physx card. Don't currently and I haven't noticed any difference.
     
  16. VanneDC thread starter macrumors 6502a

    VanneDC

    Joined:
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    Location:
    Dubai, UAE
    #16
    The 8800gt outperforms the gt120 by a mile, so I don't recon I'll be needing one of them. I also know that physx on the extra gpu isn't where I am concerned about, iam thinking the extra 512mb of gddr3 on the 8800 might come in handy with large Photoshop/3d max files?

    Would that help out at all?

    Either way I guess I need both cards anyways as I'll need 3 dvi ports.

    Well I am realy swaying towards the 285gtx.
    Need to make a decision on it today, so if anyone has some good reasons to steer clear of this gtx285, please let me know as I am purchasing it later today...

    Thanks in advance for all the feedback and hints/talking points I maynot have thought about.

    Cheers
     
  17. goMac macrumors 603

    Joined:
    Apr 15, 2004
    #17
    VRAM doesn't work like that. Only the VRAM on the card you're using will get used. It doesn't add together.

    Photoshop also doesn't use VRAM, RAM only.
     
  18. CaptainChunk, Feb 7, 2011
    Last edited: Feb 7, 2011

    CaptainChunk macrumors 68020

    CaptainChunk

    Joined:
    Apr 16, 2008
    Location:
    Phoenix, AZ
    #18
    To clarify for the OP, in a situation where you have three monitors running on two graphics cards (with two monitors presumably running on one graphics card), the VRAM on one card would only be allocated to the monitor(s) connected to it.

    So in a situation such as this, you would preferably connect two of the monitors to the GTX 285 (which has 1GB of VRAM) and the third one to the GT 120 (512MB). Effectively, each monitor will have 512MB of VRAM to work with.

    But also understand that only one GPU (the primary) will do any actual graphics processing. The secondary card would only serve the purpose of providing the third monitor with its own frame buffer - useful in situations where you have multiple windows open with lots of detail, regardless of whether the application utilizes GPU acceleration or not.

    In the grand scheme of things, VRAM matters a little more than one might think. OS X most certainly utilizes VRAM by itself, as even 2D windows are OpenGL accelerated. And for the record, Photoshop indeed has GPU acceleration in the form of OpenGL. While the performance advantage of having OpenGL enabled in Photoshop is often considered negligible, it's still there.

    This Anandtech article is a good read that explains the importance of VRAM in finer detail.
     
  19. goMac macrumors 603

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    Apr 15, 2004
    #19
    Back in 2001? Maybe. These days? Not really.

    As the article notes, one window requires about 7 megabytes.

    How many windows does one need to open to fill up a 1 gig or 512 megabyte card? And that's for holding all windows in VRAM at once, which OS X doesn't actually do (it swaps in and out inactive apps.)

    Back in the day, when cards had 16, 32, or 64 megs of RAM, VRAM could be VERY important.

    These days, as long as you have 512 megs of VRAM, you're more than good enough for non gaming.

    I think this graphic says enough:

    [​IMG]

    70 simultaneous active in VRAM Safari Windows is all a 512 meg card can handle? Yes, that's certainly anemic. :)
     
  20. CaptainChunk macrumors 68020

    CaptainChunk

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    Apr 16, 2008
    Location:
    Phoenix, AZ
    #20
    Okay, I get your point. But it would be interesting to see those same graphs utilizing multiple complex windows open in more demanding applications (like say, Photoshop). I still think the Anandtech article serves a purpose to an extent. While I know very few people who actually run 70+ simultaneous Safari windows on a single display, it still illustrates that VRAM gets utilized even in the more "generic" of situations.
     
  21. VanneDC thread starter macrumors 6502a

    VanneDC

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    Jun 5, 2010
    Location:
    Dubai, UAE
    #21
    Got it, so it is actually handy to have to 8800gt run a screen from it's own frame buffer. That's good. Well, I recon I am sold on the gtx as it will surely play more nicely with the gt than an ati variant.

    Pretty much a done deal I would recon. I'd like to thank everyone for thief input into this thread. Cheers
     
  22. goMac macrumors 603

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    Apr 15, 2004
    #22
    Actually, under Mac OS X and Windows 7, an ATI and NVidia will play together no problem. Under Vista there were issues, but they were fixed with Windows 7.

    The GTX 285 is discontinued, can't be purchased anymore. Given that, I'd recommend going ATI. I can't even find anywhere online to buy one, and the last posted price was nearly $500, MORE than the 5870.
     
  23. gpzjock macrumors 6502a

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  24. VanneDC thread starter macrumors 6502a

    VanneDC

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    Jun 5, 2010
    Location:
    Dubai, UAE
    #24
    My mate is upgrading to a 5870, so am getting his for cheap and a few cans of jack n coke to boot.nap looking forward to giving that gtx285 a run on the little pro.

    I can't afford the 5870, so it was either the 5770 or the 285...
    The 5770 still goes for 400 plus au dollars here... So the gtx 285 it is

    : )
     
  25. VanneDC, Feb 8, 2011
    Last edited by a moderator: Feb 8, 2011

    VanneDC thread starter macrumors 6502a

    VanneDC

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