I know there have been a million threads about TF2 performance getting worse and worse with each update, but the problem I'm having is a bit more peculiar.
I used to be able to run TF2 at 1680x1050 and a constant 60FPS, but in the past few months, I've encountered random performance drops. The frame rate hangs around 40-60 most of the time, but then, every few minutes, it drops to 15-20 FPS for a minute or so. This happens regardless of what's happening on screen - I'll be in the spawn when the framerate suddenly drops, and it can pick back up to 60FPS during a huge firefight. It also isn't affected by lowering settings - my max FPS is slightly higher at 1280x800, but it still dips to the teens every few minutes.
I thought this may have been the result of another process spiking its CPU usage periodically - antivirus, for instance. I added Steam to the exceptions list on MSE, and it didn't help. Finally, I decided to run resource manager in the background to monitor what it was suddenly choking my PC. Turns it, it's Team Fortress 2 itself which is having random CPU spikes.
I tried to printscreen a CPU spike, but I found I wasn't able - strangely enough, TF2's CPU usage goes back to normal as soon as I alt-tab out of the game. So here's the best screenshot I could muster up:
I'm at a complete loss of how to deal with this problem. Obviously, my computer can run the game just fine - it does so 70% of the time. But the sudden framerate drops are making the game nearly unplayable - lowering settings doesn't help, and alt-tabbing in and out of the game gets annoying.
It's mystifying. I love Team Fortress 2, and I want to keep playing, but this is just ridiculous.
Here are my specs:
Core 2 Duo T7700 @ 2.4 GHz
4GB RAM
Nvidia Geforce 8600M
Windows 7 Ultimate 64 bit
EDIT: also worth mentioning that enabling Multi-Core Rendering improves the problem somewhat, but also introduces mouse-lag.