when i installed SS2008 on my computer, it did runs a bit slow and the screens moved per second, even i had the right requirements, but i saw something on my video card driver that i could choose:
''optimal performance'' or ''optimal quality'' my computer was set on ''optimal quality'' and when i changed it to ''optimal performance'' the game runs so smooth as it can.
so if someone has the correct system recuirements but the game still runs slow, just search for something like what i told in the driver setup, maybe that will help