AV programs suck, hate i cant just disable McAfee

totally trashes my performance. pins at 100%. 12 hrs idle time, 3 hours Mcsheild. anything over 1% cpu is suspect. i hate that i have to have it to attach to a vpn...i know how to avoid viruses and also how to remove if i ever get one. hate that i can not disable it and run only when i have to. hate that the windows OS is blamed for being so slow when its the AV program -throw AV on a Mac and see how it sucks. why cant they just keep an indexed database of scanned objects and leave them alone when they dont change?