must be a short vid then 
but back to topic: Irc is something you can keep on as long as your pc is on. it uses about 5mb of ram and 0.000001% of your cpu time.
so unless your still using a pentium 2 with 64 mb ram (or less)you wont get any lag from it when playing any modern game.
its no msn/aim/icq. you can leave a message and get a instand reply or a late one.
so dont join ask something and then leave 5 sec afer you asked.
Beta: Latin for "still doesn't work".