BenQ G2400W?
 

So I'm thinking about buying this, but I've got an old gfx card: Radeon 9800 Pro 128 mb. I'm not planning on playing any games (with maybe the exception of portal here and there), but just want it to watch movies and tv shows and have more screen space. Can my gfx card run it or would I need to update it? I forgot what motherboard I have.. how do I check that in Windows XP SP2?

CPU-Z at CPUID will allow you to check what kind of mobo you have.

What I've seen through searches, it should be able to. Just don't expect that resolution in Portal.

P.S. Thought about getting a 22' inch, which is around 150 dollars cheaper?

You won't have any problems in Windows and stuff, though you'll definitely won't be getting Portal to run in 1920x1200 nicely. Of course, there's no reason why you can't play at a lower resolution, except that it won't look as nice of course.

BenQ makes pretty good monitors, by the way, though my 22" does have slightly annoying color banding.

Read: Digital Visual Interface - Wikipedia, the free encyclopedia

I don't know the native resolution of that LCD but probably you hit the single-link DVI limit with this config. I doubt using analogue connection is something you want to try (I really don't recommend it because of the two additional AD/DA conversion steps).

Better check what kind of DVI link you have and the maximum resolution you are able to supply to the LCD. Not using native resolution in non-gaming mode is always a BAD idea.