MP 1,1-5,1 MP 1,1: Issues w/ Radeon 7950 (GV-R795WF3-3GD Rev 1.0)

[Ezzio]

Hi Guys.

I tried to use a flashed Radeon 7950 (model in subject) on my MacPro 1,1 (2006) flashed to 2,1 and running El Capitan (OSX 10.11.6).

With the 7950, the system gives the boot screen and reaches the login screen without any problems. This, however, is where the issues start.

As soon as I enter my password in the login, the computer gives me the spinning wheel, starts to load the desktop and then suddenly returns to the login screen. There are times that the MP1,1 lets me play with the Desktop a few seconds before randomly returning to the login screen.

The MP1,1 had a 5870 (1GB) before and, as soon as I put the 5870 back, all these issues disappear - magically. So I guess, the issue is related to the 7950. On a side note, booting the MP1,1 in Safe Mode (holding shift at boot), allows me to use the 7950, yet running quite slow and showing some random glitches when moving windows around.

Can you help me understand if I have a chance of using this videocard on my MP1,1?

Thanks.

 

[h9826790]

Do you have any other OS to try?

You are running a patched OS. It's hard to tell if that cause any problem for a "new" GPU.

 

[Ezzio]

Do you have any other OS to try?

You are running a patched OS. It's hard to tell if that cause any problem for a "new" GPU.

I have Lion. I noticed that Lion was also kind of unstable. On a side note, in "Safe Mode", El Capitan kind of works. The video is very slow though.

 

[h9826790]

I have Lion. I noticed that Lion was also kind of unstable. On a side note, in "Safe Mode", El Capitan kind of works. The video is very slow though.

Lion has no driver for HD7950.

Safe mode disable many GPU related accelerated functions. Most likely that why it works buy laggy.

 

[Ezzio]

Lion has no driver for HD7950.

Safe mode disable many GPU related accelerated functions. Most likely that why it works buy laggy.

Dunno, Lion was working but it looked just like Safe Mode. For example, when you move a window, you see the GPU literally redrawing the background, at the speed of a Commodore 64.

So, what do you suggest? Is it a driver problem? El Capitan is supposed to have a driver for the HD7950, am I wrong? Alternatively, what GPU would you put in a 1,1 to have something a bit better than the 5870?

 

[h9826790]

Dunno, Lion was working but it looked just like Safe Mode. For example, when you move a window, you see the GPU literally redrawing the background, at the speed of a Commodore 64.

So, what do you suggest? Is it a driver problem? El Capitan is supposed to have a driver for the HD7950, am I wrong? Alternatively, what GPU would you put in a 1,1 to have something a bit better than the 5870?

Lion has no driver for 7950. What you see is from the Mac EFI UGA (that's exactly what a flash card can provide)

Non patched El Capitan has driver, but I don't know how about yours. El Capitan can't run on a 2,1 natively. If you patched your OSX, then the GPU driver may be broken.

7950 should able to work on a 2,1 if you do it correctly.

https://forums.macrumors.com/threads/just-upgraded-mac-pro-1-1-2-1-to-radeon-7950.2087083/

 

[Ezzio]

Lion has no driver for 7950. What you see is from the Mac EFI UGA (that's exactly what a flash card can provide)

Non patched El Capitan has driver, but I don't know how about yours. El Capitan can't run on a 2,1 natively. If you patched your OSX, then the GPU driver may be broken.

7950 should able to work on a 2,1 if you do it correctly.

https://forums.macrumors.com/threads/just-upgraded-mac-pro-1-1-2-1-to-radeon-7950.2087083/

My El Capitan is patched, indeed. Is it possible to simply reload the the GPU driver, so that I can overwrite the broken one? I really dread the idea of reinstalling everything.

Thanks.

 

[Macschrauber]

El Cap on 1.1 should work with a 7950.

Maybe your card is defective. Double check it in a supported machine.