Click on the Apple button on the top left corner, and click "about this Mac".
A window with the specs of your Mac should appear.
For Windows
Type dxdiag in the search bar in the Windows menu and click dxdiag.
Click on the "Display" tab of the dxdiag window to see your graphics card information.
RUINER
Reikon Games
 75
Minimum:
2520
CPU: 
Intel Core i5-760 (4 * 2800) or equivalent / AMD Athlon II X4 645 AM3 (4 * 3100) or equivalent
Click on the Apple button on the top left corner, and click "about this Mac".
A window with the specs of your Mac should appear.
For Windows
Type dxdiag in the search bar in the Windows menu and click dxdiag.
Click on the "Display" tab of the dxdiag window to see your graphics card information.