Google this: Tomshardware RED DEVIL.
Gaming today would, by most folk get the 1 to 2GB dedicated video memory. 256MB sounds like what was done over a decade ago.
I need a good computer for gaming and i have 400€ (500 USD) for it. Requirements: 2,5GHz prosessor, pretty good graphics card for gaming (256Mb dedicated ram) and at least 4Gb ram.