This is what I can find for specs on it on Ebay. Oddly enough Nvidia themselves do not list this card or show its specs:

Chipset GPU Nvidia Geforce 9300 GS
Memory 512MB DDR2
Core Speed 567 MHz
Memory Speed 900 MHz
Interface PCI Express
Direct X Support DirectX 10
OpenGL OpenGL 2.0
RAMDAC 400 MHz
Memory Bus 64 Bits
Output Ports D-SUB & DVI & HDTV Out

I have an Nvidia GeForce 8400gs card installed now. Here are the specs I can find for it:

GeForce 8400 GS
Core Clock (MHz) 450
Shader Clock (MHz) 900
Memory Clock (MHz) 400
Memory Amount 256MB
Memory Interface 64-bit
Memory Bandwidth (GB/sec) 6.4
Texture Fill Rate (billion/sec) 3.6

However the 8400gs I have has 512mb on it rather than 256mb.