The cheapest graphics card you can play it on is an NVIDIA GeForce 7100 / nForce 630i. In terms of game file size, you will need at least 1 GB of free disk space available. To play 3DMark 11 you will need a minimum CPU equivalent to an Intel Core 2 Duo T5600. 3DMark 11 system requirements state that you will need at least 1 GB of RAM.
3DMark 11 will run on PC system with Windows Vista and upwards.