Mac Pro "10.8 blank screen when wake up using DP"

[Amethyst]

The problem started when i connect my Dell U2711.
With flash 5870 displayport the system works fine .
When my pro sleep i can't wake display up.
(Get only blank screen). But system wake up fine
(i can remote desktop to control my pro)

Help me please!

 

[Number Curtain]

The problem started when i connect my Dell U2711.
With flash 5870 displayport the system works fine .
When my pro sleep i can't wake display up.
(Get only blank screen). But system wake up fine
(i can remote desktop to control my pro)

Help me please!

Try disabling "DDC/CI" in any of your displays that have it.

 

[Amethyst]

Try disabling "DDC/CI" in any of your displays that have it.

Can't solve my problem. T_T

But i've found some interesting msg.
when i've power on the system before display.
My display will shown this.

 

[666sheep]

This seems to be common issue with 5770/5870 when using mDP/DP, IMO not related to 10.8 (first reports started with 10.6, when these cards did appear on the market).

Disconnecting and plugging back display cable does the trick in some cases.

https://forums.macrumors.com/threads/1054925/

Apple was aware about this roblem, and there's their solution:
http://support.apple.com/kb/TS3533

 

[Amethyst]

This seems to be common issue with 5770/5870 when using mDP/DP, IMO not related to 10.8 (first reports started with 10.6, when these cards did appear on the market).

Disconnecting and plugging back display cable does the trick in some cases.

https://forums.macrumors.com/threads/1054925/

Apple was aware about this roblem, and there's their solution:
http://support.apple.com/kb/TS3533

Thanks but it doesn't solves my problems. T_T