MP 1,1-5,1 Graphics card problem

[Baggyp]

Hi all

Just joined and looking for some help.

i have a 2008 mac pro running 10.11.6 El Capitan, my graphics card fan started to get super noisy but worked just fine- so i decided to replace it like for like. (ATI Radeon HD 2600XT).
My problem is .... replacement card will only work if the old card is still installed!
if i remove the old card nothing. System information tells me that both cards have drivers installed(replacement card in slot 1 running two monitors, old card in slot 4 with nothing connected)
Can anyone tell me what i need to do so that I can remove my old noisy card and just have the replacement one running.

many thanks

 

[KeesMacPro]

Did you buy a Mac version HD2600XT?
If it's a PC version it will not work.

There are several cards that perform much better , and can be found used on e.g. eBay ,maybe take a look here for compatibility:

GPU Compatibility List for cMP

Content: 1. Summary 2. Information on common GPUs that can be used in cMP 3. GPU power consumption 4. Color compatibility 5. Flashing nuances 6. What to choose? 7. Useful links. 1. Summary 1.1. There are 50+ GPU types that are compatible with cMP (classic MacPro = Mac Pro 1.1-5.1/...

forums.macrumors.com

 

[Baggyp]

Did you buy a Mac version HD2600XT?
If it's a PC version it will not work.

There are several cards that perform much better , and can be found used on e.g. eBay ,maybe take a look here for compatibility:

GPU Compatibility List for cMP

Content: 1. Summary 2. Information on common GPUs that can be used in cMP 3. GPU power consumption 4. Color compatibility 5. Flashing nuances 6. What to choose? 7. Useful links. 1. Summary 1.1. There are 50+ GPU types that are compatible with cMP (classic MacPro = Mac Pro 1.1-5.1/...

forums.macrumors.com

thanks, i think its from a pc so that would explain..

 

[Nguyen Duc Hieu]

I have a Gigabyte HD6670 2GB and it works out of the box with both OSX 10.7.5 (Lion) and 10.11.6 (El Capitan).
I've just bought a second-hand Gigabyte GTX680 2GB OC (35$, pretty cheap compared to the new price).
At first it couldn't boot to El Capitan. I had to swap back to the HD6670 and boot into windows 10, turn off the machine from windows 10, re-insert GT680. Then reboot by Boot Camp Control back to El Capitan.
Now it booted straight into El Capitan with no glitch at all.

You can try a better (still very cheap) PC card. No pre-boot configuration support (Boot screen) of course, but it might just work out of box.