Nvidia NForce 680i overclocking

so i take it no one has tried overclocking with this motherboard. Maybe this should be a hint to me to get a new one hahaha!!!

I know this is an old as hell post, but since i'm having issues with the board and stumbled upon this post, i just thought i'd reply in case you're still having problems and might check it...

1)
FSB 1066 @ 8x = 2133
FSB 1800 @ 8x = 3600 and not 2300.......
to calculate use this (FSB) / 4 * (Multi) = CPU Freq
Q6600 has a top multiplier of 9x... stock speed should be 2400
dropping the multiplier does not always help. There are FSB holes in 680i's

2)
make sure memory is unlinked and is running at it's stock speed (ie 533Mhz, 667Mhz, 800Mhz etc. some boards would show half that speed... that's fine, just depends on manuf. in the end it's the same.)
make sure the memory is always running at it's rated voltage and not at what the board sets it at. This board has a tendency to undervolt the memory. (ie Corsair Dominators will run at 1.9v instead of 2.1v)

3) with any overclock, you have to increase the voltage of a CPU and FSB. At FSB that you're trying to run, it'll be around 1.45v-1.50v and a ridiculous temps. Q6600 has max voltage at around 1.40-1.45 if my memory doesn't give up.

Setup that works 90% of the time on this board.
FSB - 1333 (1199 is another freq that should work 99% of the time. If 1333 is unstable, you can try this one and just up the freq few Mhz at a time)
Multi - 9x
Memory - 800 (if that's your memory's rated speed and make sure it's set to unlinked)
CPU Vcore - 1.30000v (could be stock ~1.26250v on some CPU's/Boards)
FSB - 1.3v
Temps will only go up a few degrees with an aftermarket cooler. Do not recommend it with a stock cooler.
if this doesn't work, begin backing down FSB few at a time until you can boot windows. Afterwards run prime95 overnight to make sure that it's stable. watch temps a few mins at the beginning of the run to make sure you don't approach 70C. ~71C is maximum factory recommended.
I personally keep "C1E Enhanced Halt State" enabled. Keeps temps and clock low on idle to increase CPU life, but in certan boards that will add overclock instability.

remember, higher FSB = always higher voltages required = higher temps. That's why it's easier to start with a high multiplier and drop it only when you hit such a wall, when raising voltage doesn't help and you need to jump a good chunk of FSB.

hope this helps if it ever get's to you