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AMD Radeon HD 7950 Mac Pro 5,1 - HDMI

kittonian

kittonian

macrumors regular
Original poster
Aug 4, 2008
178
53
Austin, TX
I have a client coming in on Monday who is stating that when he plugs in his LG 34UM95 display or his projector, neither receives any signal from the AMD Radeon HD 7950 graphics card. We have tested this card over DVI and it works flawlessly but have not yet tested the HDMI port.

After searching the web with every term I could think of for this issue, I could not find one person who has said the card worked perfectly but not over HDMI.

The system is a 12-core dual 2.93 with 32GB of 1333mhz RAM and a Samsung EVO 840 SSD drive. I just put a fresh install of Yosemite on it Wednesday and when he took it home and tried to hook it up to his monitor, it showed "no signal, power saving". I had him hook up his laptop (MBP) via HDMI and the monitor came alive and worked perfectly.

So, it's not his monitor or his HDMI cable. It's definitely something up with this card.

Any thoughts on things I should be checking (other than the obvious reset the PRAM and make sure both power cables are properly plugged in for the graphics card)?

Thanks!
 
You get the boot screen. This was a machine we purchased used that we spruced up a bit and resold, but it came with the video card, which I assumed was the "mac edition" as the guy we bought it from wasn't exactly a computer genius.

Update: I just saw what the "Mac Edition" card looks like (all white) and the card in this machine is red, so I guess it must be flashed.
 
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kittonian said:
You get the boot screen. This was a machine we purchased used that we spruced up a bit and resold, but it came with the video card, which I assumed was the "mac edition" as the guy we bought it from wasn't exactly a computer genius.
Click to expand...

OP , do you have an actual picture of the graphics card ? That'll help to determine its identity (genuine Mac Edition or a flashed PC card .)

If it is a flashed PC card (and if it's not a reference flashed PC card) , there could be an issue with port mapping in the ROM . Or, it could just be a badly flashed PC card .
 
The client is coming on Monday afternoon so I do not have the machine in front of me, however, from all the genuine mac edition card photos I've seen online, they are all white/gray. The card in this machine is red.

If it is badly flashed would you still get the boot screen and the DVI port working? Do I need a PC to reflash the card properly and ensure the ports are mapped correctly or can I do it on a Mac? We do not have a PC unless I take one of our Macs and install bootcamp/windows on it (which I would rather not have to do if at all possible).
 
Apple Logo at Start Up means there is EFI present on the graphics card .

But it doesn't mean someone did a perfect job flashing the card .

Genuine Mac Edition AMD 7950 cards look like this :

SAP100352MAC_gall1.jpg


You obviously have a flashed PC Card . You need to contact the individual who flashed the card or re-flash the card yourself .

I would recommend flashing in a DOS environment , not in an OS X or Windows environment . You should learn how to do this and it is too complex for me to discuss it further here . Good Luck !
 
I would have no idea who flashed the card. Though I am by no means a flashing expert, I have flashed NVidia cards before and it's never been an issue. I have no problem re-flashing the card myself, but I guess I need to setup a Windows machine to do so (I was hoping to be able to use Zeus on OS X). Looking on the Netkas forum I have found a ROM that says it should work, so I guess that's what I will try, though other threads I read suggest that the HDMI port not working is par for the course with these flashed cards.
 
kittonian said:
I would have no idea who flashed the card. Though I am by no means a flashing expert, I have flashed NVidia cards before and it's never been an issue. I have no problem re-flashing the card myself, but I guess I need to setup a Windows machine to do so (I was hoping to be able to use Zeus on OS X). Looking on the Netkas forum I have found a ROM that says it should work, so I guess that's what I will try, though other threads I read suggest that the HDMI port not working is par for the course with these flashed cards.
Click to expand...

You need to get in there and find out what card it is exactly. I'm hoping for your sake its based on reference design and the rom will be able to fix the port mapping issues.
 
rawweb said:
You need to get in there and find out what card it is exactly. I'm hoping for your sake its based on reference design and the rom will be able to fix the port mapping issues.
Click to expand...

If his card is not reference , then all bets are off . His card may just not have all functions supported in an EFI environment . The best flashers can dig into the ROM and try to re-map everything .
 
The issue is in the framebuffer personalities inside the AMD drivers. No way to remap them without messing with the OS X system kexts (and thus violating SIP).

What you can do instead is modifying the EFI on the card to inject wrong ioreg entries (or non at all). This will make the AMD drivers treat the card like a unflashed PC card, which will usually enable all ports regardless of their physical mapping.
Most of this is described in this thread over at netkas, I think I also provided a EFI which does exactly that.
 
Thank you to everyone who responded. The DVI and both mDP ports on the card work just fine so instead of worrying about using the HDMI port, the customer opted to leave things alone, and he purchased HDMI->mDP cables which solved all his issues.
 
EDIT: Missed the fine print on how to check myself and it DOES support Metal, well dang.

New Question: Still have the non-flashed 7970 in my 2010 MacPro. High Sierra running fine but telling me to update to Mojave which requires graphic cards that support Metal. Does the 7970 support metal?

Official Support Page: https://support.apple.com/en-us/HT208898#cards
 
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magnumdb said:
EDIT: Missed the fine print on how to check myself and it DOES support Metal, well dang.

New Question: Still have the non-flashed 7970 in my 2010 MacPro. High Sierra running fine but telling me to update to Mojave which requires graphic cards that support Metal. Does the 7970 support metal?

Official Support Page: https://support.apple.com/en-us/HT208898#cards
Click to expand...

The 7970 DOES support metal, and Mojave works very smoothly with this card. That said, I’ve heard conflicting reports that the latest Mojave Installer may not (10.14.1).
 
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