As my specs states, I have a rather low end video card (Geforce GT 520) and CPU (Celeron) and on Windows 7, disabling Aero/compositing would speed up many games noticeably (Bioshock infinite, TF2, NFS and more)...

I read that Windows 8 won't allow it to be disabled at all unless you remove video drivers (kinda useless in this case).

Why didn't Windows 8 have a option to disable it at least temporarily while a game is running as Windows 7 had?