The Lenovo x220 comes with an Intel i5-2520m processor. The machine has a 1366×768 LCD. Many games natively support the LCD, other games may only support 1280×720. The i7 version of the X220 has the game graphics as the i5 CPU.
The HD 3000 (Sandy Bridge GT2+ core) includes support for DirectX 10.1 and OpenGL 3.1.
Classic games will run OK on low settings with the HD 3000 graphics. The 12 unified shader cores are not very powerful. 129.6 GFLOPS is the maximum.
The HD 3000 is between the Radeon 5470 and 64xx series in terms of capability, We estimate that it is about 3x as powerful as the Radeon 3470 in general terms.
The HD 3000 has 32MB dedicated memory but it designed to support shared system memory and the L2 cache. The machine came with 4GB of RAM which is enough for the HD 3000. Additional memory is helpful generally.
TRYING OTHER GAMES
The HD 3000 only fully supports DX10 which shipped with Windows Vista. The HD 3000 does have WDDM 1.2 which shipped with Windows 7. The X220 shipped well after Windows 8 was released.
Generally DX9 works best on the HD 3000, DX10 games may run too slowly. The HD 3000 lacks the support for revamped DX11 API.
The HD Graphics 3000 playing Dragon Age: Origins is a huge step forward at 1024×768. It’s 70% faster than Clarkdale integrated graphics, and fast enough that you can actually crank up some quality settings if you’d like. The higher end HD Graphics 3000 is also around 26% faster than a Radeon HD 5450.
With the turboboost, the HD 3000 has enough performance for many classic titles. The HD 3000 shares the L2 cache with the CPU which helps a lot to overcome the limited number of shader cores. Games that can use the AVX instructions will run better on the Core i5-2520m with the HD 3000 graphics.