The sales site does not go into that detail. The User's Guide does not specify either. A user will have to post their findings.

I wonder if you would have more luck using a DVI to display port cable?

Very dissapointinly it seem to give max resolution of 2048*1152 in my system... and it's a bit soft even at max sharpness setting... GPu is Asus GTX560 and the monitor is connected with miniHDMI wich both should do the resolution 2560*1440

I can't believe Dell have stranded us without a DVI connector then don't even have the decency to tell us if HDMI will work at full resolution.

Yes it does, as long as it is HDMI to HDMI connection. I cannot get it to work with DVI to HDMI cable.