Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Three Monitors Two Video Cards One Problem

R

revron08

macrumors newbie
Original poster
Mar 9, 2010
8
0
Hi,

I have a MacPro 3,1 (2008) with the standard issue ATI Radeon HD 2600 XT installed in slot 1. I want to have three monitors cause I'm a dork like that. I purchased a second identical radeon card and installed in slot 2 (16x). Then I connected my monitors (2xNEC EA241WM) to the new card in slot 2 and fired up the machine.

Everything worked fine except there was no picture on the monitors. I then disconnected the monitors from the new card and plugged them into the original card (slot 1) and they work as they always have.

In System Information under the Graphics/Displays tab, it shows "ATI Radeon HD 2600 XT" in slot 1. Slot 2 just says "Display" It indicates that there is No Kext Loaded. I don't know what that means. I also do not know why the second card is not working. Are these two things related?

Do I need to install a driver for the second card even though it is the same as the first? Is there some slot protocol that I don't know about that says video cards have be installed on odd number slots, or some other such secret code?

I feel confident that I am not the only one to try to do this and even more confident that someone out there reading this knows exactly what I need to do to make this work. Any and all help is greatly appreciated.
 
Not sure but could be your second Radeon 2600XT is defective. Before I had 2 Radeon 2600XT on my 08 Mac Pro and both worked fine. Or you can try removing the card, wiping the card and reinstalling it
 
666sheep said:
This "new" card seems to be a PC version. You need Mac/flashed one.
Click to expand...

This seems like the most likely case. If it is, I would recommend putting the "new" 2600 in slot 1, taking out the other card, and following one of the flashing guides. It's generally not recommended to have 2 ATI cards in the computer when attempting to flash 1 (you could flash the wrong card). I defer to the tutorials for further information.

Another possibility: I also had some really strange driver problems when I placed a Radeon 5870 and a Radeon 6870 in my Mac Pro. The only way to fix it was to take one out.
 
slughead said:
This seems like the most likely case. If it is, I would recommend putting the "new" 2600 in slot 1, taking out the other card, and following one of the flashing guides.
Click to expand...

99% of 2600XTs have 64K chip. Flashing these requires fitting new 128K EEPROM. Remaining 1% are Mac ones ;)
 
666sheep said:
99% of 2600XTs have 64K chip. Flashing these requires fitting new 128K EEPROM. Remaining 1% are Mac ones ;)
Click to expand...

Well I guess that's that then (I've flashed a lot of cards, obviously never a 2600 though). Do the 2600's work like the other PC Radeons--that they go dark until boot? Or do they just not work at all.
 
Thanks for all the help, everyone.

I bought the "new" card from a guy off Craigslist. I saw it work in his MacPro 3,1 and watched him take it out and give it to me. So, it would seem that it is not a PC version, and it certainly was working a few hours before I installed. Could it be that I seated the card incorrectly? Would System Info show generic info like this if it were seated wrong, or just nothing at all?

Thanks again, everyone.
 
So, last night I shut down my computer and left it powered down all day. I just got home and fired it up and the new card shows up. This is perplexing because I had done several restarts, and full power cycles before I posted on this board. I guess it just needed a few hours to think about it.

Anyway, thanks everyone for your help. I really do appreciate everyone's attention.
 
there's a good chance the fan on your new card is clogged with dust and causing it to overheat. I'd suggest removing it and vacuuming out the fan. Running a card with a clogged fan is a sure way to kill a video card (if it isn't mortally wounded already)
 
A much better buy would have been a used PC GTX570 which would be much faster than the 2600XT. I have a Mac GT120 plus a PC GTX6570 in my 3,1 & run three monitors with OS X 10.8.4.
 
revron08 said:
So, last night I shut down my computer and left it powered down all day. I just got home and fired it up and the new card shows up. This is perplexing because I had done several restarts, and full power cycles before I posted on this board. I guess it just needed a few hours to think about it.
Click to expand...

i-rui said:
there's a good chance the fan on your new card is clogged with dust and causing it to overheat. I'd suggest removing it and vacuuming out the fan. Running a card with a clogged fan is a sure way to kill a video card (if it isn't mortally wounded already)
Click to expand...

rabidz7 said:
Try using just the card with issues and taking the working one out.
Click to expand...

I'd like to offer a different course of action. As someone who's experienced these type of intermittent unexplainable issues before and attempted to chase them down, I think you should just take it as a blessing and try not to think too hard about it. :D Congrats on the new purchase, that sounds like a cool setup.
 
666sheep said:
They don't work until flashed.
Click to expand...

Not exactly true.

I have apple's 2600xt and sapphire's pc 2600xt, and If I install both then pc 2600xt being initialized by efi rom from apple's 2600xt just fine and works well in osx.
 
netkas said:
Not exactly true.

I have apple's 2600xt and sapphire's pc 2600xt, and If I install both then pc 2600xt being initialized by efi rom from apple's 2600xt just fine and works well in osx.
Click to expand...

Right, I've forgotten about helper card method.
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back