7970 in Mac Pro 4,1

[lf90]

Hey all,

New to the forums but a long standing MacRumors reader. Wondering if anyone else has come across a problem with third party graphics cards and a maximum of 2 screens active at any one time?

If I plug say all 4 screens into the 7970, two are blank, two are correct. Say I turn one of the screens off, now one of the blank ones comes on. All ports seem to be working for this reason but not simultaneously.

Anyone else experienced similar - I spent a while browsing the osx86 forums but alas nothing helpful. Reports are it works fine in 10.8.3 but not 10.9 so Im tempted to try it to find out.

Interestingly it comes up as a AMD Radeon HD 7xxx in System information.

Thanks for any knowledge or help in advance

 

[slughead]

I believe this is a problem with the way AMD does multiple monitors, you may need "active" adapters. I believe if you swap your "passive" adapters with "active" ones, your problem may be solved.

To enable more than two displays, or multiple displays from a single output, additional hardware such as DisplayPort-ready monitors or DisplayPort 1.2 MST-enabled hubs may be required.

http://support.amd.com/en-us/recommended/eyefinity-adapters

 

[lf90]

Thanks for the reply, I'm going to go and buy a few as Im still using the standard Apple Mini-diplayport to DVI adapters. Oddly enough though, the two via DVI turn off then the mini-diplayport's adapters are being used so its almost as if the DVI is being ignored when the mini-diplayport is plugged in

I will post back results - thanks slughead ^_^