30 is very playable. You want to shoot for something over 60. Once you get higher than that, you really can't tell the difference because your eyes have a refresh rate of their own

Even you clean up your computer, you're not going to have much of a difference in framerate. Freeing up disk space is not going to lighten the load the game puts on your CPU by much. Nonetheless, it's still something I recommend doing on a regular basis. Use CCleaner to get rid of temporary files and such. You can let it keep your cookies and whatever so not all of your browsing data is lost.

Bucky says:
Once you get higher than that, you really can't tell the difference because your eyes have a refresh rate of their own

Nope. We don't see with a "refresh rate of X", because the light around us doesn't have to be created by CPU or GPU.
Okay, you can ask, so why we can't see things such like bullets from weapons? Because our brains need some time to interpret the received informations, but it still cannot be named as "refresh rate".

Yeah that's true, eyes themselves do not have a refresh rate, but the computation of their images takes a finite length of time, which can be interpreted as such. Nonetheless, my point is remains valid. Above a certain point we can't tell what the refresh rate of a screen is.

This 'certain point' is actually pretty low - something like 18 or 19 fps.

lol?

at 30 fps I can clearly see the difference compared to 20fps.

Yeah, srivier, that number is far too low. I can definitely notice the difference between 20 and 30 at least ..

normally the Human Eye starting to see a "movie" at 25 FPS, lower FPS than that and you can see single pictures. Myth Busted!!!


P.S.: There is also no Intel Core-ix series processor at Socket 775 ....... only core2

Some of the first movies actually had framerates around 18 fps. But you're right - you can still see flicker at such low fps rates.

Now the update allow us to put shadows at "low", my problem doesn't exist anymore!