(WIN8) Noticeable Framerate Loss Under Strange Circumstances

For some strange reason, my framerate is poor unless the Windows cursor is being displayed, which fixes the problem until it’s hidden again.

Normal Gameplay

http://cloud-2.steampowered.com/ugc/882976114532812356/FB86C52E0F4641D9A73FB061FECFDDD9C54B0B96/[/t]

Avg: ~45fps

Menu Displayed (C Key Held, Pointer Showing)
[t]http://cloud-2.steampowered.com/ugc/882976114532814826/D65DF3243139ACAEE5AE20684FC17A2398F60A3D/

Avg: ~60fps

Is this just a Source glitch under the new operating system? Or am I doing something wrong here?

I’m not noticing this and I’m running Windows 8. Are you sure it isn’t that vignette I can see in the picture?

I’ve since disabled that and tested the game without any addons whatsoever, and the results are the same.

Though actually… The same thing’s begun happening in Team Fortress 2 now that I’ve noticed it. I’m going to poke around to see if maybe this is a graphics card problem…

[editline]t[/editline]

Still nothing. It’s only Source games that do it, I’m looking through a few possible factors.
Framerate also seems to increase slightly when there are a large number of textures with alpha being displayed on the HUD…

Now that is the exact opposite of when my framerate drops.

try removing your entire garrysmod folder (steam/steamapps/accountname/garrysmod)
also, verify integrity.

EDIT:Derp, I should go to sleep…
If this occours in multiple games this is obiviously not the problem. What’s your specs?