21 Inch Nvidia 9400 iMac

I just reinstalled the game on this computer, and I also have WoW installed. However, ever since I did so, I have noticed incredibly reduced performance in both games. I am getting short, choppy bits of lag every few feet in both games, and some of the time my abilities either fail to go off or are delayed. Is there a way to fix this?

Also, since my graphics card is integrated, i can't take it out. Is there a way to improve the computer's performance if I already have 4 GB of RAM?

Did games always lag like that or did this start recently?

This started occurring since I got a new copy of City of Heroes, and since patch 3.3.5 in WoW. I'm not sure which caused it, but there is definitely a noticeable increase in lag now.

Edit: I got the new copy of CoH on Monday the 21st, and patch 3.3.5 came out on the 22nd. Games never lagged like this before.

Are you using Steam? It sounds like there's some kind of background process chipping away at the processing power. Try this:

1. Close all applications.
2. Open Applications > Utilities > Activity Monitor.
3. Click the CPU % column and sort so the highest amount is at the top.
4. That's probably your culprit.

After that check your Login Items (in System Preferences > Accounts) to see if anything there matches the high CPU use, and remove it.

EDIT: Before you try all that, reboot and see if it improves the speed. It may just be a stuck wine/cider process.

I'm not using crossover or anything, it's the mac client.

Did you just upgrade to Snow Leopard patch 10.6.4? I think there's supposed to be some kind of graphics performance problem with the video driver in that release that affects some graphics chipsets. Maybe it's that issue.