Guild Wars 2

Mountain lion is actually a little bit slower because of how it runs extra stuff in the background, but I have been a power mac user for about 7 years now and can say the best thing I can recommend is make a brand new user account and repair disk permissions with disk utility. On your new user account don’t open any third party applications you may have downloaded and to only open applications you have to have (like the game, internet browser, BUT NOTHING ELSE). Your new account should be for gaming and gaming only! Those steps are very important!!! You should also reset your NVRAM/PRAM and reset the SMC while you are at it. (it’s very easy, and consists of holding some keys down during boot! google it) If you are still having problems after all this you can re-install just the operating system and it will replace corrupt system files. (Try to avoid this if possible because serial numbers might reset on some applications and some system settings.)
Apple is far superior than Winblows and I have all my settings on max except for shadows(because i could care less about shadows) and I get around 30-40 fps all day.
If you want absolute MAX PERFORMANCE follow these steps….
1. Backup your hard drive on external HD
2. Erase your internal HD and with disk utility do a 1-pass write of 0’s on the disk.
3. Install a fresh copy of Mountain Lion
4. Install the game and you are GOLDEN!!!