OS X Sierra & Sapphire HD 7950 Mac

AlDavis

macrumors member
Original poster
May 7, 2007
56
3
Is the OS X Sierra compatible with the Sapphire HD 7950 Mac Video card?
Thank you.
 

h9826790

macrumors G5
Apr 3, 2014
14,264
6,862
Hong Kong
Apple broke HD 7xxx support on MacPro3,1 in Mavericks and never bothered to fix it despite the existance of that "7950 Mac Edition", so this question definitely valid...
IMO, yes and no. The 7950 driver is broken since Mavericks on the 3,1 (it still works, but poor performance due to a power management bug). However, the HD7950 Mac Edition card never says that it support the 3,1. It only said it's compatible with 4,1 and 5,1. So, we can't really blame Apple even thought that's a official Mac Edition card but can't work properly in the 3,1.

And since the 5,1 is on the Sierra support list. So, I will assume the 7950 is fully supported on the 5,1 as well.

Of course, it's still better to do some test / research before upgrade. Who know what Apple will do. But 3,1 + 7950 is not a good example, because this combination never exist officially.
 

bbrown_sc

macrumors newbie
Feb 24, 2017
3
1
I have just installed a new Sapphire HD 7950 Mac Edition in my Mac Pro 4,1 flashed to 5,1 running sierra 10.12.3. I have it attached to a Dell P2715Q 4K Monitor. The mac won't boot if the monitor is attached with a DisplayPort cable. No boot screen. The mac chimes and then nothing. You need to power it down with the power switch. You can boot the Mac without the DisplayPort cable attached, then attach the cable. It will display defaulting to 1920x1080. Using preferences, you can adjust it to 3840x2160 @60Hz. But this process has to be done each time you boot the machine. At the 4K setting I also notice the screen will flicker occasionally.

The system will boot (including boot screen) with an HDMI cable but the max resolution is 3840x2160 @30Hz

If anyone knows a solution to get it to boot (including boot screen) to 3840x2160 @60Hz using DisplayPort that would be most appreciated. Both Sapphire and OWC were of little help.
 

bbrown_sc

macrumors newbie
Feb 24, 2017
3
1
@Fl0r!an, thank you very much for your response.

Is not being able to boot at all (regardless of boot screen) when attached the Dell P2715Q attached via DisplayPort considered "normal behavior"? You would think Sapphire or OWC would know this is a known issue.

I have an email request into MVC for solution for this.
 

AlDavis

macrumors member
Original poster
May 7, 2007
56
3
I notice that my card flickers from time to time, by not with Windows. Any ideals why the flickering?
 

bbrown_sc

macrumors newbie
Feb 24, 2017
3
1
Mine flickered too. I finally returned the 7950 and got a Nvidia GeForce GTX 980 from MacVidCards.com. What a world of difference from performance to the ability to run 4K @60Hz (with boot screen) on the DisplayPorts. It's really nice to have a somewhat modern card with drivers for both OSX and Windows (bootcamp).
 
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owbp

macrumors 6502a
Jan 28, 2016
717
241
Belgrade, Serbia
I notice that my card flickers from time to time, by not with Windows. Any ideals why the flickering?
Mine flickered too.
My 7950's were ok, but i have flickering (whole screen flashes) on MSI R9 280X.
Turns out that it is a problem with power states of the card, when going from idle mode into some desktop animation (dock popup, launchpad, safari maximize screen, etc) and it only happens in 2D. It is rock solid without any artifacts or flashes in 3D apps and under heavy load.

If that's the case, the easisest thing is to edit those power states with VBE7
You'll have to rebuild EFI part afterwards though.
 

h9826790

macrumors G5
Apr 3, 2014
14,264
6,862
Hong Kong
I notice that my card flickers from time to time, by not with Windows. Any ideals why the flickering?
That's a known software bug on the 7950 Mac Edition card with single monitor attached

Some possible work around at this moment

1) flash the card with a modded ROM

https://forums.macrumors.com/threads/which-graphic-card.1762908/#post-19463227

2) connect more than 1 display to the card (some Display Emulator device should also work)

3) keep the Mac running under high GPU demand
 

glopez007

macrumors newbie
Aug 8, 2014
1
0
@Fl0r!an
Do you know of any AMD graphic cards (Mac edition or flashed efi edition) that works with the 5K Dell monitor UP2715K using the requisite two displayports simultaneously? I have this 5K monitor but in order to get 5K at 60Hz, I have to use Nvidia cards with web drivers. Thanks.


btw, I'm using cMP5,1.
 
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Mac9527

macrumors newbie
Sep 15, 2017
1
0
兲朝
I have just installed a new Sapphire HD 7950 Mac Edition in my Mac Pro 4,1 flashed to 5,1 running sierra 10.12.3. I have it attached to a Dell P2715Q 4K Monitor. The mac won't boot if the monitor is attached with a DisplayPort cable. No boot screen. The mac chimes and then nothing. You need to power it down with the power switch. You can boot the Mac without the DisplayPort cable attached, then attach the cable. It will display defaulting to 1920x1080. Using preferences, you can adjust it to 3840x2160 @60Hz. But this process has to be done each time you boot the machine. At the 4K setting I also notice the screen will flicker occasionally.

The system will boot (including boot screen) with an HDMI cable but the max resolution is 3840x2160 @30Hz

If anyone knows a solution to get it to boot (including boot screen) to 3840x2160 @60Hz using DisplayPort that would be most appreciated. Both Sapphire and OWC were of little help.
Wow, I finally found a problem and I exactly the same person, the difference is that I use the NEC EA275UHD, you solve this problem? I was forced to put the 7950 switch to the Windows mode, in addition to no start screen all normal, of course, the screen also said that occasionally flash about.
 

h9826790

macrumors G5
Apr 3, 2014
14,264
6,862
Hong Kong
Wow, I finally found a problem and I exactly the same person, the difference is that I use the NEC EA275UHD, you solve this problem? I was forced to put the 7950 switch to the Windows mode, in addition to no start screen all normal, of course, the screen also said that occasionally flash about.
If you force the VRAM to run at 1250MHz even at idle (or any fixed frequency), there will be no more shuttering.

But that will require BIOS edit, and reflash the ROM.
 
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AlDavis

macrumors member
Original poster
May 7, 2007
56
3
If you force the VRAM to run at 1250MHz even at idle (or any fixed frequency), there will be no more shuttering.

But that will require BIOS edit, and reflash the ROM.
If I reflash the rom, will it affect Windows in a negative way? Sometimes when you do something to one thing, then it effect another. Just asking...
 
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