Pragmatist: Sorry that I'm resurrecting a slightly older thread, but I feel more attention should be brought to this issue. Basically, whenever the game autosaves or you decide to save manually, the game creates a brand new save file EVERY TIME. If you look at your save game folder, you'll see that the folder literally blows up in size. My folder was 4 GBs large and people have also reported their folders to be multiple gigs in size. Remember, this isn't even the game's folder, this is just for saves. The problem is compounded by the fact that each sav file is anywhere from 5-16 mbs large. Because saves do not overwrite, this adds up fast.
If I recall correctly, this was also a problem in the first Witcher. Perhaps some of you have noticed the more you play the game that hitting the esc key to access the menu takes an increasingly longer time. Undoubtedly, it's because of the ballooning save game folder and the time it takes for your harddrive to access it.
It would be nice if the save system could be amended in a patch to be more streamlined and allow for simple overwriting. Creating a completely new save every single time is simply inefficient and a waste of harddrive space.
Tons of topics on this, also take a look at the sticky at the top for the list of mods, there is a save game utility there to clean up your save file if you do not feel like doing it from your documents folder.