I was in doubt what the maximum Intel e7400 2.8Ghz Overclocks are there out there? I don't have the 7400 but I do have the 7200 as well as mine is running @ 4Ghz 9.5 X 422 (that’s 58% overclock) as well as it's 80 F in here and idles about 43C I am using a freezer 7 pro with arctic silver thermal paste that CPU has a 11.5x multi, which high multi is overwhelming (IMO) for overclocking. Though you should push up your vcore abit, and you should be capable to hit 4.0 GHz fairly easily. The E7600 can strike 4.7 on air I’ve herd, so yours should be able to hit 4.0 24/7 with no trouble.