I've started playing TF2 recently and I've found that it lags. A LOT. It never used to lag even on high settings. It seems that it has to do with my cpu usage, cos process lasso claims that my pc's responsiveness drops greatly while i play. its so laggy that everything stops for maybe 1-2 seconds. im pretty sure it isnt my internet because its worked b4.
You haven't been throttled by your isp or something. If it ran fine before on the same pc then it's not anything to do with the pc. Try starting a game on your own server to see if it still lags that will tell you if pc or connection is the problem.
Stuttering in TF2 (with corresponding stuttering in audio), where the game seems to pause for a few seconds, usually isn't lag but an issue on the client side. Try using steam's built-in defragmenter on your Source content. This is important--TF2 relies on not just HL2, but Episode 2 content as well, so make sure to get those.
