Radeon HD 6850 /w latest drivers near 15 fps in Gmod and TF2?

Been having problems with Garry’s Mod and TF2 specifically, but generally, with all Source Engine games.

Frame rates are stuttering on a modern setup:
-8GB PC1600
-Phenom II x4 @ 3.0GHz
-Radeon HD 6850
You get the idea.

I will say that I have just installed Windows freshly on this computer replacing Lubuntu, which is now on my laptop.
Before I reinstalled Windows, every game played on the Windows install before was 200fps in older games like these.

Now with the reinstall, games stutter. There are no other visible problems however.

I have just one theory for now:
The newest versions of the Radeon drivers are causing this, 13.0 was just released and I’m using it.
Should I rollback to a previous driver?

EXTRA: This is NOT normal, TF2 is lagging, not on max settings, but while on LOWEST, same for Gmod.
ttt_67thway_v3 lags on lowest graphical settings.

If you need extra info I will share it with you.

Did a quick Google search and did not find anyone complaining about new AMD drivers.

Someone in fast threads told me to post in tech support, but it was a Gmod/ TF2 related issue so I came here.

I think tech support is the best way to go.

You might be bottlenecking, check up on that. If not, see if you’re using multicore rendering.

Send me the log when you save a DXDiag file.

Multi core rendering is forced off in GMod. (yes, even if you select enable it won’t actually enable)