My son's 2600k drops to 1.6 Ghz whenever it's not under load. Are you placing the puter under load or just looking at its idle speed after waking it up ?
Yes, I have placed it under load. I have turbo boost disabled but Energy Saver still enabled, so it will normally clock down to 1.6GHz. But when under load (and the overclock working), it jumps to my normal 4.5GHz. Then, after putting the computer to sleep mode and waking it back up, it only jumps to 3.4GHz.
I'll try hibernation mode.