No 6xxx fixes seem to work. Can't get above 1920x1080

[iknowcodesoup]

Can't get above 1920x1080

I can't seem to get the 2560x1440 that my new monitor supports.

GE=yes works fine and I have QE working without a problem.
It's just that the Display pref panel doesn't show the higher resolutions that the monitor is capable of.

My setup:

ML 10.8.2 (RAID0)
Gigabyte 6850
Yamakasi Q271

My system shows the card as 'AMD Radeon HD 6xxx 1024 MB' and the monitor shows up as only 'DVI'.

I've tried the following and with the result:
1a. Replace ATI6000Controller.kext with the original (8.0.51) instead of what I had (8.0.61)
1b. Results in the OS giving an unsupported kext error and rebooting into only one resolution of 1024x(something) At least with the .61 file I can get 1080p.
2a. AtiConfig, AtiPorts with 4-5 different frame buffer options
2b. No change.
3a. Third-party apps to force a higher res like SwitchResX
3b. Results in my resolution defaulting to 800x600 on boot and not showing any custom resolutions that I've put in.
4a. Force HiDPI
4b. Only shows 960x540, 800x600, 800x450 HiDPI modes.
5a. Try a different port!
5b. HDMI, DisplayPort, and DVI all work and only give 1080p.

I've read through the forums and haven't found any posts that say that their card works perfectly fine except the higher resolutions without some other problem that I'm not having.

[EDIT]
Okay, so after giving up on the App Store possibly not working afterwards I removed my device-properties key from the boot.plist as a few threads have mentioned.

I can now get the card to show up as 6850 using Duckweed or a few others, but depending on which one certain ports don't work.
The biggest problem is that no matter what option I choose I still can't see anything above 1920x1080.

Any thoughts? The card says that it's capable of that resolution but I'm having my doubts.

 

[iknowcodesoup]

SOLVED No 6xxx fixes seem to work. Can't get above 1920x1080

Bumping this....

So I wanted a newer video card anyway and purchased a GTX 680. It also now works with CL and all it's bits... yet I STILL cannot get above 1080.

The monitor is more than capable of it, but I have yet to install Windows on one of my spare drives to test it out there to make sure that it can actually do what it claims. I haven't read of anyone else having that problem.


So WHY with a brand new GTX 680 4GB can I not get above 1080???


A little help here would be much appreciated.

SOLVED Apparently the 680 card won't do 2560 over the display port. Hooking it up directly to a DVI-D port works perfectly.

So the solution is to buy a better graphics card My 6850 wouldn't do this res over the DVI-D port.