Eyefinity issue

[CrisisHawk]

I currently have a HD 6850 GPU, a 1440x900 19" monitor and a 1600x900 20" monitor. I am also getting another 1440x900 monitor and a display port > DVI adapter. 

 

So far whenever I try eyefinity with the two monitors I have, it scales down the 1600 one to 1440 giving me a resolution of 2880x900 and stretching the image a bit. I plan to use that one as a the center monitor once the 3rd one is delivered and I am trying to find a way to force it to stay at 1600 when in eyefinity so the total resolution of the 3 monitors should be 4480x900. I've tried using Google but couldn't find quite what I was looking for.

 

I have updated the GPU to the latest drivers from the amd website, there is an option in there for set custom resolution, but that appears to just be a list of pre-sets with no way to add to it.

 

Thanks in advance for any suggestions, it's not a significant issue but one I'd like to fix all the same.

 

(If it makes a difference, I am considering upgrading to a GTX 770 in a few months time.)

 

[Analog]

If you upgrade to a GTX 770 to use surround all 3 monitors must have the same resolution and the same refresh rate. Otherwise it won't work at all. Bear that in mind. 

[CrisisHawk]

I was thinking of getting an Nvidia card next for the Physx, but multi monitor is more important to me and if eyefinity just works better than surround I might go for a 7 (or wait for 8) series card then.