From another thread about systems and graphic cards...
http://www.subsim.com/radioroom/showthread.php?t=101690
My system:
High Performance Core 2 Duo E6600, 2.40 GHz
Chieftec LCX-01 Workstation
LC-POWER 550W, 120mm, 14 dB
ASUS P5B Deluxe, P965, DDR2/GLAN/RAID/1394a/WiFi motherboard
Intel Core 2 Duo E6600, 2.40 GHz / 1066 MHz, 4 MB
Kingston HyperX DDR2, 800 MHz CL4, 2x 1 GB
ASUS EN8800GTS TOP/HTDP/512M
Creative SB X-Fi Xtreme Gamer
2 * Maxtor DM 21, 250 GB, 7200 rpm, 16 MB, SATA II
Lite-On SHM-165P6S DVD Writer, 16x DL
Lite-On DVD-ROM, 16/48x, bulk
Multi Reader 15-i-1, intern, USB 2.0
1.44 MB floppydrive
Standard Cooler, 120x120x25, 26 dBA
Logitech MX1000 Laser Cordless Mouse
D-Link DI-624 108Mbit Wireless Gateway
ViewSonic 19" LCD 1280*1024 max
I used to have a BFG 1gb video card IIRC, but it broke down, and my usual pc shop didn't have another 1gb video cards at the time (March 2009). But they explained me that that having the extra 512mb wouldn't really render much better graphics. The GPU is of greater importance. So even though, my video ram was half of what I had before, the speed of the GPU was increased.