So I have had my iMac for nearly 3 years now and it has done a great job and ran perfectly. I also got into games and started playing League of Legends. Now everything has been running extremely smoothing never had problems until yesterday morning. I usually play around 60 fps and now it drops to 30 fps and doesn't return to 60. After that then I also noticed other games were not running smooth and the computer in general was feel very slow. Im lost at what to do to fix this as I have repaired the disks and there is no errors and did a hardware check and everything seems fine. Any help would be greatly appreciated. Also ask if any info is not clear.