omg, I had this ongoing “lag” issue in TF2 whereby my fps would drop dramatically in a fight in TF2 (team fortress 2) game.

Things get more frustrated when I recently upgrade my graphic card from the old 8600GT to the GTX260 and the lag problem does not go away!

Its only recently that I came across this thread in steam forum that suggest a fix to this problem.

if you have a similar setup like mine

• Intel Core2Duo E6320
• 4GB RAM
• Windows 7 Home
• GTX260
• Onboard Realtek soundcard
• MSI P65 Neo2 motherboard

and encounter the following symptoms…

• lag or shutter after 2-3 seconds when you walk in a straight line in the game
• framerate drop to 10+ in heavy fight
• sound shutter in heavy fight
• ping spikes randomly

for the following steam games…

• Source Engine Games (Team Fortress 2 (TF2), Left 4 Dead, Counter Strike Source (CS:S, CSS))
• Heroes of Newerth (HoN)
• Call of Duty Series (CoD), possibly including Modern Warfare
• Overlord Series (Overlord, Overlord: Raising Hell, Overlord 2)

perhaps you may want to try the following method and see if the problem would go away.

1. Open regedit
2. Go to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile
3. There will be an entry for network performance throttling, default value is 10; set it to FFFFFFFF hex (willl look like 0xFFFFFFFF to the right of the entry
4. Reboot