Well, you haven't really explained in detail how you got, or get the lag. There are a number of things that could add to the lag and resolve it. The type of connection you use to access the internet is usually the first thing to look at. If you are using a wireless connection, try and move closer to the router so the signal strength is better. Better yet, run a ethernet cable from the router to your computer. Running significant amounts of applications at the same time will use up memory processes and slow your CPU down. Try cutting back on the number of applications you have open.
I hope this helps.
Cheers, dafin0
