Same problem as you describe with the 305T and the Radeon HD4850 - tried 2 manufacturers for the HD4850 and both reported a max resolution of 1280x800 and refused to go higher (except in the fake "sliding desktop" scheme). I should be getting an EVGA 640-P2-N828-BR GeForce 8800 GTS tommorrow and will see if that works.
This same monitor on the same computer system DOES work!!! with
Radeon X1900 XTX
ATI FireGL V3300
so I don't see why these other drivers get it wrong.
ATI responded asking me to install the monitor driver. The monitor driver is NOT needed according to the user manual, and the driver is not available for download from Samsung. If someone can provide the driver for me, I can continue with ATI to solve the problem. Is it, as they claim, on the CD (which I cannot find now)???
I recently bought a Samsung SyncMaster 305T 30" LCD Monitor. I also bought a nVidia geForce 7600 GT video card, because it was on the list of "compatible" cards on the Samsung website. This monitor has 2 native resolutions, depending on the video card and connector cable being used: 1280x800 or 2560x1600. At first I couldn't get above 1280x800 because I was using a single-link DVI cable. Samsung mistakenly included a single-link DVI cable in the box instead of a dual-link and they still haven't responded to my complaint, but that's an entirely different story.
I went and got a dual-link DVI-D cable. I still couldn't increase the 1280x800 resolution. I proceeded to update the nVidia driver to the OMEGA version. Now I can set the resolution to 2560x1600, but it extends the desktop image past the actual monitor screen (basically it's still 1280x800 viewing space, but multiplied past the screen to equal 2560x1600 pixels), and I have to pan left/right/up/down with my mouse to see the whole desktop. I am at wits end with this issue, and would be eternally grateful to anyone who can assist me in getting that beautiful 2560x1600 resolution into the viewable area. Windows XP is the operating system. Thanks you so much in advance!!!