Got a tip for us?
Let us know
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
OS X Sierra & Sapphire HD 7950 Mac
- Thread starter AlDavis
- Start date
- Sort by reaction score
Thank you for respons. I am actually leading the biding on the card on Swedish website Tradera ( part of eBay ). Current bid, 1kr ( about 15 cent US ) . So it’s DIRTY CHEAP
What display will replace the Apple Cinema since it is no longer in production? Just curious...
It's a bit misleading to say "it works". Yes, it works at some resolutions, with some monitors. If you want to run a 4K screen at a flicker-free 60Hz, for which you must use a DP1.2 port, you will find that as soon as it sees even one 4k/60Hz monitor, the cMP just locks up and won't boot. The old trick of attaching another lower rez screen doesn't help.
The solution is to either switch the card to PC mode (thank Heaven that's even possible) and forget the boot screens, or connect over HDMI 1.4 or DP 1.1, at 30 Hz only, which isn't really too cool. Oh, a third option is to swiftly plug and unplug cables during boot, at least until you fry a port, and change settings after it's booted. That's a lot of work, so I wouldn't say that "it works", unless you don't mind being limited to lower resolutions in a 4K world.
With the firmware switch in PC mode the HD7950 supports two 4k/60Hz screens in a cMP just fine over its 2 mini DP1.2 ports with no flicker or flashes or anything. No point in paying extra for the "mac" version firmware that doesn't work.
The solution is to either switch the card to PC mode (thank Heaven that's even possible) and forget the boot screens, or connect over HDMI 1.4 or DP 1.1, at 30 Hz only, which isn't really too cool. Oh, a third option is to swiftly plug and unplug cables during boot, at least until you fry a port, and change settings after it's booted. That's a lot of work, so I wouldn't say that "it works", unless you don't mind being limited to lower resolutions in a 4K world.
With the firmware switch in PC mode the HD7950 supports two 4k/60Hz screens in a cMP just fine over its 2 mini DP1.2 ports with no flicker or flashes or anything. No point in paying extra for the "mac" version firmware that doesn't work.
Last edited:
I flashed a HIS 7950 for boot screens and also to the 5.0 GT/s link speed. Work beautifully with boot screens to a 24" iiyama mDP with adapter to DVI.
Also the other mDP port works ( no boot screen ) to a Mitsubishi 23" mDP to HDMI.
Running 3 monitors possible.
Got it for ¥8,000 + sales tax here in Japan. Nice card and doesn't use too much electricity at idle.
Link to the 5.0 GT/s link speed mod.
( Post #199 )
https://forums.macrumors.com/thread...-and-nvidia-card.1547340/page-8#post-24856990
( Note : Now runs X-Plane 10 & 11 faster with the 5.0 GT/s link speed mod. )
Also the other mDP port works ( no boot screen ) to a Mitsubishi 23" mDP to HDMI.
Running 3 monitors possible.
Got it for ¥8,000 + sales tax here in Japan. Nice card and doesn't use too much electricity at idle.
Link to the 5.0 GT/s link speed mod.
( Post #199 )
https://forums.macrumors.com/thread...-and-nvidia-card.1547340/page-8#post-24856990
( Note : Now runs X-Plane 10 & 11 faster with the 5.0 GT/s link speed mod. )
Nearly every GPU, even some officials ones, have their quirks and incompatibilities. If people had to describe every single possible issue when responding, nobody would bother to respond at all.
Certain things should just be reasonably assumed, like if you want to use your 4K monitor with a 6-year old card designed before 4K monitors were prevalent, you might want to ask specifically if it will work with 4K monitors.
Here it is 2018, June, and this stuff still works. I flashed the ROM referred to in this post to my Sapphire HD 7950 Mac Edition with flicker issues on MacOS High Sierra and they are resolved. It was a little tricky making a bootable CD, but XP in a Virtual Box instance to the rescue on that front. Just wanted to note the fact that this thread may be old, but it's still relevant.
The information I used to get the CD working: http://forums.crucial.com/t5/Crucial-SSDs/How-I-Made-the-Mac-Bootable-DOS-CD/td-p/5994
Last edited:
Yes, running one here. Mine was flashed & resistor modded by MVC.
Works great, no screen flicker, pretty fast too.
AFAIK, only the genuine Sapphire HD7950 Mac Edition card has this flickering issue.
From memory, I never see any other 7950, 7970, R9 280, R9 280X... has this issue. I flashed a R9 280, and resistor mod it by myself. No problem at all.