4K on MP3,1 - if possible: Which graphics card?

Discussion in 'Mac Pro' started by ThoreEliasson, Oct 22, 2014.

  1. ThoreEliasson macrumors newbie

    Oct 21, 2014
    Hello everyone, I'm Thore.

    this is my first post over here though I've been reading the forums for quite a while. I've spent several hours yesterday to get into the topic but I would really appreciate your input on this topic. Thank you!

    One of my machines is a MP3,1 (8core, 16gb, 2xSSD, ooooold GT-120 graphics, 10.9 soon 10.10) which still does a very good job at various tasks. It is mostly used for stationary Adobe Photoshop and Lightroom work.

    I would like to attach a 4K display to it which of course requires a DP1.2 graphics card. It would be lovely if the graphics card would not only enable 4K but enhance the workflow in Photoshop as well.

    As far as I understand Photoshop's Mercury Engine relies heavily on OpenCL and disregards any CUDA capabilities making AMD cards the more interesting option on paper. At least up until the 970/980 which is not fully supported at the moment.

    But what I still have not figured out is if 4K is supported by Mac OS for cMP at all?

    If it is, the question is which graphics card to buy:
    As this is not my main computer I do not intend to invest too heavily. I do not play any games whatsoever. So it's just Adobe Lightroom, Photoshop and web browsing.
    I understand that except maybe the newest cards all nVidia cards are supported if one can live without the boot screen (which I can). It seems to be a different story with AMD which is unfortunate because they are probably faster in my field of application?

    Here's what I am looking for in a graphics card:
    • Enables 4K on MP3,1
    • Performance plus in Adobe LR/PS
    • Works within the MP power specifications i.e. no external PSU and no overload on internal circuits (if I am correct this means maximum 225W, maximum 2x6pin power connector)
    • No hacking, flashing or workarounds if possible
    • I would of course like to not have to worry about it being supported in an upcoming OS update (if say xyz is supported now, will it always be supported in the next iterations of mac os?)
    • Price (new) between 100 and 250$ ideally. The less, the better.

    Do you have any info for me or suggestions for graphics cards?

    Thank you so much guys!

  2. MacVidCards Suspended

    Nov 17, 2008
    Hollywood, CA
    Several threads on 4K in cMP.

    I know because I started them or posted in them.

    A wealth of info, ready for harvesting.

    Keep in mind "4K" has different meanings depending on which display.

    Do some googling on "MST" vs "SST" and 30 Hz vs 60 Hz. IPS vs TN vs IGZO
  3. ThoreEliasson, Oct 22, 2014
    Last edited: Oct 22, 2014

    ThoreEliasson thread starter macrumors newbie

    Oct 21, 2014
    Hey MVC, thank you for your reply!

    I'm afraid this is not going to get as easy as I had hoped huh? :-/
    Reminds me of building my first PC as a teenager many, many years ago hrhr.
    But maybe you can help me clearing things up a little?

    The display in question is the Samsung U32D970Q. I could not figure out though which transfer mode this display uses or requires to display 4K60Hz (I do hope that it does not rely on the 2-display workaround? Edit: Have found a report that says the display works using SST 60Hz).

    Do you know if there are graphics cards out there that provide a "worry-free" solution in that they are supported by MacOS and deliver full 4K60Hz SST via DP with said Samsung display?

    Any help is hugely appreciated, thank you so much!
  4. MacVidCards Suspended

    Nov 17, 2008
    Hollywood, CA
    You are halfway there.

    As I have an Asus 321, I can't help you.

    You just need to google the combo you are interstd in and see what comes up.

    Good luck
  5. ThoreEliasson, Oct 24, 2014
    Last edited: Oct 24, 2014

    ThoreEliasson thread starter macrumors newbie

    Oct 21, 2014
    Hello MVP,

    I could not find any reliable info about the combination of said display and Maxwell-based cards :-/

    What I have learned in the meantime:
    1. The display works with SST 4K/60
    2. OpenCL ist important for Photoshop's Mercury engine.
    3. Maxwell ups the OpenCL game for affordable nVidia cards
    4. Maxwell is supported in 10.10. + Web Drivers
    5. Maxwell cards are operating well within the 225W/6-pin specification and do not need either bravery or an external PSU.

    These questions remain:
    1. 4K on cMP seems to be supported now (10.10.) without further fiddling, correct?
    2. With 750ti/970 - is OpenCL automatically supported/unlocked with 10.10 + Web Drivers or do I need to activate it first in any way (drivers, os or application)?
    3. If 10.10. is 4K enabled and if Maxwell is supported -> does this automatically mean that I can drive said Samsung display via DP with say any generic GTX 970 card?

    I really appreciate your help – I have spent some considerable time researching the whole topic now but it's not that simple starting from complete scratch I'm afraid :-/

    Thank you so much!
  6. MacVidCards Suspended

    Nov 17, 2008
    Hollywood, CA
    I really can NOT offer any confirmation on SST 4K as I purposefully got the same display that Apple has promoted in hopes of best driver.

    I know that AMD cards have had better MST support but that you can enable 4k 60hz on Nvidia cards with a tweak.

    Maxwell support is still moving forward. The OpenCl numbers beat anything from AMD, including 290x. (980 beats it by 20% or so)

    I don't believe CUDA is on board yet but should be soon. I can put a lovely boot screen on a 750 but haven't got the 970/980 figured out yet. I imagine we will, took us several weeks for GK110 but we got it, so I am hopeful.

    Keep in mind that a 3,1 has a glass ceiling of sorts with GPUs. I can tell you for a fact that a Titan Black will give me 55fps on Uningine Valley in a 4,1 on Extreme HD preset, but on a 3,1 no card beats 35 fps. So a GTX680 gets same score Titan Black does in that OpenGL test. Cards scale below that number, but they all stop at 35 fps.

    And my 3,1 has the dual quad 3,2 CPUs, only other thing holding it back is 667 ram. I may try yanking all 667 ram if I have enough 800 left to run and see if that helps, point being that there is a limit to what a GPU can do.

    Had a guy recently get a 780 6gb for X-plane. He was disappointed that it didn't give him a big boost. Then I noticed in a screenshot that he still had 2.4 CPUs.

    With any update, it is important to figure out what your real bottleneck is. Reading actual accounts of other pros is best. If some guy posts that they used part A with part B and got result C that is usually a good indication of what you can expect with same parts. People rarely lie about such things.
  7. ThoreEliasson thread starter macrumors newbie

    Oct 21, 2014
    Hey MVC,

    thank you for all your input. I have now ordered the budget solution –a 750 ti. On paper and with OpenCL that should give ma a performance boost of around 35x while a 970 would have given me around 90x boost. 3 times faster is a lot. But I thought that if I have to wait 10s for a GPU intense filter to render now this number will go down to 0.3s with the 750 and 0.1s with the 970. 0.2s difference is not worth more than twice the money was my thinking.
    This is of course based on photography tasks. It would be a different story with 3D and video editing I suppose.
    So I am curious to find out how it all plays out in the field.

    I found the graphics card to be the bottleneck because the cpu barely ever has anything more to do than idle around while I am waiting for a slow UI and filters. We'll see if this changes –*I am really hopeful!

    OpenCL is supported right out of the box for the 750 ti with 10.10 and Web Drivers right?

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