Which is better? GeForce 8600 GTS/Radeon X1700SE...

Hi All,

We are about to buy a new computer and are looking at a Dell and an HP. I
don't want to start a Dell vs HP argument, but one of the components that I
am weighing into my decision is the graphics card. I realize that neither
of these is probably great, but want the best I can get.

The Dell XPS 410 has the Nvidia GeForce 8600 GTS w/ 256 MB memory.
The HP m8000y has the ATI Radeon X1700SE w/ 512 MB memory.

While I have been able to find some info on the GeForce, I know nothing
about the Radeon.

Or, would I be better off just getting the cheapest card option available
and buying my own?
I believe the Dell has a 375 watt PS and the HP has a 350 watt PS. What
could I get for either of those machines that would be better than the
above? I really lust for the GeForce 8800 GTX, but I have read that I would
need a much greater PS, and is a little pricier than I can go. (it is an
available option on the Dell, but is $700 more--and I thought it needed a
greater power supply anyway......)

Please go easy on me, I am not extremely well versed.......I just know
enough to be dangerous. Any and all help is greatly appreciated.


Thanks,

Cindy