I should mention that there is a vast difference in the 3D performance of the Intel onboard graphics between the previous generation and the current. You mentioned that you can play your game decently on a 945 motherboard at home. To get similar performance you will need nothing lower than the X3000 onboard graphics. The X3100 is preferable and there is even a newer one with the Q35 mini-itx. The X3100 has shaders while the X3000 does not. Both have Directx9 support. Older MBs (like the 915) probably won't have directx support and even if they do, will suffer horribly when trying to do any 3D stuff. They were made for 2D.