dx 8 and 9

Since my lenovo is pretty bad right now and i get 20-30 fps on everything low 800x600, should i force it to run dx8? and whats the difference between dx 8 and 9 in quality, panfrie said u cant see flickered  invisible spies now if u chose dx 8

Generally you will see very little difference. Water is affected a lot, and D3D9 has two-sided stencil support that can be a great benefit.

But no, you should not notice much difference, and I cannot imagine why spies would not flicker on DX8. It has support for the alpha channel on mapped textures, so...