[matrix_unloaded]

I have a machine that has one graphics card at the moment. It is a Dell XPS 430. The system has 3GB RAM and Intel Quad core processor at 2.33GHz. The graphics card is ATI Radeon HD4670 at 512 MB. I am thinking of upgrading to 1GB. I was wondering:
1. Are Dual Graphics cards better? eg. if I had 2x512MB cards would it be better than 1x1GB card?
2. If dual are better, can i just put any 512 MB graphics card in the other slot or must I use the exact same model to achieve dual graphics.

Information much appreciated.

[BG-0]

2x512 MB (4670) cards are better, 1 GB memory (on a 4670) only gives better performance with high resolutions like 1920x1200, to an extent, as you really can't expect a 50-70 $ card to run a new game really fast on a 24", 300 $ monitor.
I am still pretty sure a Dell does NOT support CrossfireX, which would be needed to run two cards at the same time to improve performance. Get a better card (not more memory, but actually better). Radeon 4770, 4870, 4890, Geforce GTS250, GTX260. Be aware that you will need a better power supply to be able to use these cards. You will also need a better ventilated case than a Dell case so that they won't overheat.

[matrix_unloaded]

Okay, well The computer has a 480 Watt power supply. Will that be enough to run 2x512 MB Graphics cards? My monitor is 21". If i can't run crossfireX, should i just get a 1GB card?

[BG-0]

No, you shouldn't just get a "1GB card". There are good, and crap 1 GB cards.

Also, post the model of the "480 Watt power supply".

boiling, boiling...

[matrix_unloaded]

I wouldt try and ge the latest nvidia or ati card 1GB. How would i find out the model number? must i open the computer's case?

[BG-0]

Open the case, look at the stickers on the side of the power supply, yes.

Which games are you playing/why are you upgrading? I can link a few good cards if you tell that...