[superfurrymonkey]

1gb ati radeon hd 4850x2 pci express or 1gb nvidia geforce gts250 pci express? 

[slackline]

1gb ati radeon hd 4850x2 pci express or 1gb nvidia geforce gts250 pci express? 

I've always preferred nVidia, but then thats 'cause I'm weird and use Linux and nVidia have always had better support.

Recently built a system with GeForce® 9500GT Super+1GB (1024MB) HDMI which cost something ridiculous like £35-40 from ebuyer, unfortunately they're currently out of stock.  Very happy with it runs Really Slick OpenGL screensavers like a dream, haven't tested any games under it as I'm not much of a gamer, just wanted some fancy eye candy from the screensavers and the X11 window manager Compiz Fusion.

[superfurrymonkey]

Is a higher texture fill rate and memory better? The NVIDIA has higher values on both and is cheaper!

[slackline]

   Generally higher/more is better in computing (unless of course you're going for an embedded low power system).

Here, Let me  that for you   (Top hit looks informative, and has a GPU card comparison feature although doesn't list a x2 version of the ATi card you're mentioning )

[superfurrymonkey]

Nice one the NVIDIA looks to be the better. Cheers