Just upgraded Mac Pro 1,1 (2,1) to Radeon 7950

Discussion in 'Mac Pro' started by Michael MP2, Nov 9, 2017.

  1. Michael MP2 macrumors member

    Nov 2, 2017
    It's a nice bump up from the 1GB 5770 I was previously using :) - Mac Pro 1,1, Piker's flash to 2,1, dual quad Xeon CPUs, 20GB memory, SSD, Yosemite (soon to be El Cap, I have it booting fine on USB.) GPU was an XFX ATI Radeon HD 5770 1GB, no boot screen, now a Sapphire AMD Radeon HD 7950 3GB, all VRAM detected.

    Installation was easy, just had to use the second power lead from the logic board. No notice in noise. There was significant and unusable flicking when in 1080p on my 42" TV monitor though... going to 1080i fixed this, but the issue returned in any game (I guess setting it back to progressive scan.)

    This was on the two minidisplayports, with adapter the HDMI to the TV. No video from HDMI directly at all. Finally I tried a three port adapter, and used the VGA on it to go to VGA to the TV. Worked great - but text was a bit fuzzy, over-smoothed. System Preferences > General > turning off LCD font smoothing didn't help, but this did (after a reboot):

    For some reason, my display was now sharp, but in a 4:3 or 5:8 resolution despite was sys prefs said. I tinkered with the 60/50Hz refresh rates, maybe a few more things, and bam, nice and sharp running at 1080p.

    Didn't benchmark that much, but what I do have:

    Geekbench 4 GPU Compute (OpenCL): 10600 to 98000 (Radeon 7950, wow)
    FurMark in CrossOver, full HD and 8x FSAA: 4 FPS to 11 FPS
    CS: Source stress test, Full HD and quality, 8x FSAA/MSAA: 163 to 289

    OpenMark didn't work on either machine, Quake's DarkPlaces timedemo was similar, and Geekbench 4 didn't support Metal tests.

    A glitch: Quake 4 had immediate, full screen distortion and froze on launch with the 7950. Doom 3 was fine - I went to Q4's .cfg file and tweaked the settings to match my GPU, now it flies :)
  2. h9826790 macrumors G5


    Apr 3, 2014
    Hong Kong
    A non reference 7950 flashed with Mac EFI ROM often kill the card's HDMI port. If there is a ROM switch on the card, you may switch the ROM to boot from it. Hopefully it's a non Mac EFI ROM, than you can have native HDMI connection. Of course, no boot screen available, but it's not required in daily use. And you can switch it back to the Mac EFI ROM on the day you need it.
  3. Michael MP2 thread starter macrumors member

    Nov 2, 2017
    Thanks - I'll take a peek
  4. USELSD macrumors newbie

    Mar 16, 2018
    How were you able to get the 1,1 booting from a USB?
  5. Macschrauber macrumors 6502


    Dec 27, 2015
    I do this all day with SSDs thru a USB - SATA Cable

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4 November 9, 2017