Severe input lag (and other issues)
Hello, everyone. After reading lots of reviews about how The Witcher 2 is the best RPG to date and all, I decided to go out and grab it, seeing as I enjoyed The Witcher Enhanced Edition as well.
So far, I like the game. But technical-wise, it has problems (even after patch 1.3), which is a fact most reviewers seem to have ignored.
First of all, after installing, the launcher downloaded and attempted to install a patch from Patcher_EFIGS.exe. But it kept on giving me the "Installed game version is invalid or incomplete" error. Luckily, downloading patch 1.3 directly told me that it was due to lack of hard disk space on drive C. (I had no idea the patcher installed files into C. I have installed Witcher 2 on a different partition.

)
After getting that sorted out, I finally decided to move onto the game. Launcher had selected Low spec by default. Okay, I thought, my PC isn't that great, so I didn't really mind that.
Specs:
Intel Core i3-530 2.93GHz
2GB DDR3-1333 RAM
NVidia GeForce GTX 460 768MB (Forceware 280.19 installed)
I know, not the best gaming PC on Earth, but I've never had any issue with other games, and as my monitor's native resolution is 1366x768, I can max out quite a few games.
Anyway, the game runs very smoothly at Medium spec, and I'm happy with how it looks. But the big issue is, there's like a half a second input delay. Especially mouse lag. Even defeating the Kayran at normal difficulty was troublesome due to this. Any idea how to fix this?
I've already read about the Mouse Smoothness and Smoothness items in the ini file, but setting those to 0 only makes things worse for me.