The following settings are known to support an E8400/E8500 at 4.0ghz and above. Again, the latest BIOS is still finicky when it comes to 45nm chips, so you may not have guaranteed success just yet.
FSB: 1800mhz
RAM: 900mhz
vCore: <<entirely dependent on the OC capabilities of your cpu.>>
vDIMM: <<entirely dependant on your RAM. Set to maximum factory setting.>>
vNB: 1.4
vSB: Auto
FSB Term: 65
All other voltages: AUTO
GTLRef doesn't seem to play as large a role here, and it shouldn't, considering it's concern is more with Quad Core cpus. Compared to the Q6600, the key difference here appears to be FSB Term. 65 (vs 25) seems to be the key for E8400s OCs on this board.
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