update your driver
and cpu doesnt take much part in games, so its probably your graphics card
Note that no graphical changes have managed to increase nor decrease my FPS.
If you didn't know, drivers affect your GPU performance and optimise how things run on it. Your PC may have too much dust in it, which would explain the gradual performance decrease.
And I did read the full post, you didn't mention drivers. So why don't you read the full post?
Note that no graphical changes have managed to increase nor decrease my FPS.
If you didn't know, my GPU performance does not change regardless to the graphical game settings. That would mean that GPU is not the case, add to that the fact that this started happening suddenly after 4.6.
And I did update my drivers, as I thought, they were up-to-date, nothing changed.
You're still playing on a P4? There's the problem, they were terrible when they were current, and beyond horrible now. TB is very CPU heavy, and your framerate depends on that more than the GPU.
Turn on the lower framerate cap option (it's in the advanced graphical options), it'll skip every other frame to make it playable. You're not going to get it running smoothly with that CPU otherwise.
I absolutely love working with this thing. It is hyperthreaded and works smoothly, it runs Source games on solid 30 FPS, but has trouble running Toribash, and only since 4.6.