lagged video/sound on 2008 Mac Pro with HD5770 and 27" ACD

[Nautilus86]

Hi, I just became the proud new owner of a 27" ACD after first updating my 3.1 Mac Pro with a HD5770. Card works perfect on my old 19" monitor but when I hooked up the 27" ACD, the video becomes sluggish and there's definitely lag present between video and audio.

Also going into Expose is pretty sluggish.
My MP: 2x2.8Ghz, 4Gb RAM, HD5770 1Gb.

Any ideas anyone? Maybe something went wrong with a driver install? See attachment.

 

[peskaa]

My 5870 says exactly the same thing, so I doubt it is a driver issue. I'm assuming your up to date with System Updates?

From the sounds of it the 5770 isn't coping with the 27" ACD, which is wrong as it should be absolutely fine. I have a 2008 with a 4870 installed and the 27" ACD works perfectly on it.

 

[Nautilus86]

Thx for the reply!

I noticed the issues after the first startup. Now I rebooted and everything is awesomely fine.