Modded 7950 or 7970 on 4K monitors?

Discussion in 'Mac Pro' started by Mad Davey, Oct 9, 2018.

  1. Mad Davey macrumors member

    Mad Davey

    Joined:
    May 22, 2017
    #1
    Hi all, I am wondering if anyone has some insight into this issue. I have two Samsung U28D590 (28" 4k monitors) I believe they are DP 1.2, but not certain.

    I have one each MSI Radeon 7970 and 7950, I have run both cards before doing the netkas EFI mod and they worked great in High Sierra over DP to produce 4k output. When I modify each card the display ports no longer work but I do get Mac boot screen over DVI and HDMI. The script runs with no errors and as far as I know they are successfully Mac EFI modded cards that might not be compatible with my monitors? The cards I purchased were cards that I have seen others online successfully mod. However no mention if they used DP or not.

    Why would modding to Mac EFI bios make the cards fail with my monitors, does anyone have insight on this so I can chase the correct problem? The bios mod was based on the rom on the cards and both cards work with my monitors over DP before modding.

    A while back, before going to a GTX980 I purchased a similar Radeon card from an ebay seller that states it was working with DP, but it did not work for me or my monitors for some reason. The seller probably did the same mod.

    Is anyone running a modded or genuine Mac 7950, 7970 or similar and using DP outputs supporting one or two 4k monitors? If so what card is it? What monitors are they?

    I'd like a decent card with dual 4k out without having to swap cards on a 5,1, and have Mojave native support. Maybe I already have it but need to change monitors? Why would the cards work pre-mod with my monitors over DP and not after?
    --- Post Merged, Oct 9, 2018 ---
    OK, so I just learned this from another thread thanks to LightBulbFun "its a known issue that the Radeon HD 79xx EFI will crash when booted with a DP1.2 monitor plugged in"
     
  2. bookemdano macrumors 65816

    Joined:
    Jul 29, 2011
    #2
    The problem is the EFI ROM. It's present on the authentic "Mac Edition" 7950 and every other 79X0/RX280 people self-flashed with an EFI ROM (because they're flashing the same ROM extracted from an authentic "Mac Edition card). That EFI ROM is not compatible with DisplayPort 1.2, which is how 4K monitors can display 4K resolution at 60Hz. If a DP 1.2 monitor is plugged into that card via DP at boot, the cMP hangs with a black screen and never boots. There is no true fix, only workarounds:

    1. Do without boot screens. If you move the BIOS switch on your cards over to the other position, they will use the UEFI ROM. You'll get a black screen at boot but once the OS loads your monitors will display properly.

    2. Settle for 4K @ 30Hz. Most 4K monitors have a setting in their menus for the DP version. Set it to use DP version 1.1 and you'll get 4K boot screens. But a 30Hz refresh rate is unacceptably slow for a lot of people.

    3. Unplug your monitors at boot (or some people have had success with turning off their monitor's power during boot) and plug back in after booting. Of dubious benefit over #1 since you still don't get boot screens that way, and seems like a lot of hassle.
     
  3. Mad Davey thread starter macrumors member

    Mad Davey

    Joined:
    May 22, 2017
    #3
    THANK YOU! .... sigh. I do not think my cards have a switch but I will check, I think that would suffice if they did.
     
  4. bookemdano macrumors 65816

    Joined:
    Jul 29, 2011
    #4
    I am pretty sure all 7950 cards do, not sure about the 7970. It's tiny so look carefully. If you google image search for radeon 7950 bios switch you should pull up some helpful photos.
     
  5. Mad Davey, Oct 9, 2018
    Last edited: Oct 9, 2018

    Mad Davey thread starter macrumors member

    Mad Davey

    Joined:
    May 22, 2017
    #5
    LOL, ok located both switches, right next to the internal connector opposite the card slot. This will hopefully get me going thanks!!!
    --- Post Merged, Oct 9, 2018 ---
    Do you know of any user Mac EFI programmable cards that support dual DP maybe even show boot screen over dp ect? k5000 looks an awful lot like its Mac counterpart, if you flash it with the k5000 Mac rom perhaps?? Upgrading to Mojave does not leave any good way to switch back to Mac OS with DP as the connection type. I saw an app that is supposed to make the os always start back to Mac OS upon power down but does not seem to run in high Sierra and likely won't in Mojave.
     
  6. Mad Davey thread starter macrumors member

    Mad Davey

    Joined:
    May 22, 2017
    #6
    As posted in another thread, I hate posting the same thing twice but feel like my topic is not quit right for the other thread: Unfortunately I want to switch between windows and Mac OS. in order to boot back to Mac OS from windows I would have to power down, hit the vid card bios switch, unplug both DP connectors, switch input on my monitor to HDMI, hold option at boot, select Mac HD, once in Mac OS select startup disk-Mac HD, shut down, switch the bios switch, plug in the DP monitors, switch my monitor input to DP, then power up. Easy right? LOL, this is kinda funny. This is if I make the upgrade to Mojave... I'm sure there is a better solution...?
     
  7. bookemdano macrumors 65816

    Joined:
    Jul 29, 2011
    #7
    The only EFI cards you will find that support DP 1.2 4K connections are recent NVIDIA cards (Maxwell, etc). The EFI for them was custom made by a company called MacVidCards, and it's not freely available. You either have to buy your card from MVC or they have a flashing service whereby you mail them your card and they flash it and mail it back.

    Pro: 4K @ 60Hz + Bootscreens - The Holy Grail!
    Cons: Expensive, Drivers are not built into macOS, so you are at the mercy of NVIDIA each and every time macOS has even a minor update. Consider that two weeks after the Mojave release, there are no NVIDIA web drivers for it, and no ETA.

    That's it. Of the two "Mac Edition" cards that were on the market years ago (the 7950 like you have as well as the NVIDIA GTX 680), neither one supports DP 1.2 connections. I've never owned a 680 so I can't say for sure if it hangs at boot when connected to a DP 1.2 monitor like the 7950, but it for sure will not display boot screens in 4K.

    This situation is why some of us were hoping that since Apple is recommending the Radeon RX 560/580 for use in Mojave that they were going to develop a modern EFI driver for those cards to provide the full macOS experience, including boot screens). Alas, that was not the case and seems like it will never be the case.

    So as you can see, once you go 4K your options are all crappy. You can have 4K @ 30Hz with boot screens (or at least no boot hangups), 4K @ 60Hz with no boot screens, or 4K @ 60Hz + boot screens but a huge hassle every time you have to install an update to macOS (and still a question mark if they'll ever release drivers for Mojave).

    I've been through all three scenarios and they all suck. I almost sold my cMP earlier this year because I was so tired of it. But in the end I've just decided to join the masses and embrace the lack of boot screens. Now that Apple has disabled FileVault entirely for the cMP on Mojave (which was the main reason I needed boot screens), there's little left to hold out for anyway.

    Wish I had better news for you but there is no perfect solution to this.
     
  8. Mad Davey, Oct 9, 2018
    Last edited: Oct 9, 2018

    Mad Davey thread starter macrumors member

    Mad Davey

    Joined:
    May 22, 2017
    #8
    It seems like keeping the 7950 with netkas mod and hook to DVI for emergencies then running a RX instead of Nvidia the rest of the time will be as good as it gets for now. It looks like I can sell the GTX980 for a good chunk still, it's an awesome card.

    Nvidia advertises DP 1.2 support on the Mac K5000, no daisy chain feature supported. I am still curious since see k5000 with Mac mods selling for around $350 on ebay, did these guys steal MVC firmware or did they simply flash the K5000 Mac bios to them, the hardware looks very much the same on those. I suspect they would support efi boot screen. Looking at benchmarks however makes them a little less desirable especially considering the cost. I've seen the Mac K5000 bios floating around, I'm assuming it's the oem not MVC version. I wonder if it's just a firmware change or do they pop some resisters off etc? https://www.nvidia.com/content/PDF/data-sheet/NV-DS-QUADRO-K5000-for-Mac-US-NV-LR.pdf and https://www.nvidia.com/content/PDF/...raphicssolutions-linecard-july13-final-lr.pdf
     
  9. h9826790 macrumors G5

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #9
    No need to power down, you can flip the switch anytime you want, even the card is running under 100% stress.

    And if you can use Boot Manager / BootChamp / terminal command to switch between OS, you can leave the VBIOS switch at the PC position, so that no need to worry about hand during boot.

    And if your monitor has DP 1.1 option, you can also set the monitor to DP 1.1 during boot, and then switch that back to DP 1.2 after the graphic card is initialised. There is non need to power down the Mac just for switching input. You can also pull / plug the monitor cable any time you want.

    In any case, I don't think you need to pulling cables for just OS switching.

    I used to use my HD7950 Mac Edition card to perform cMP firmware update with my Samsung CHG90. All I need to do is just set the monitor to DP1.1. Let it complete, and set it back to DP 1.2. No power down required, no pulling cable required. Just press few buttons on the monitor.
     

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8 October 9, 2018