Because we've had a few, "my E6600 won't turn on at 4.0GHz" questions I updated my "A simple guide......"

Before we start, don't even bother reading this guide unless you have a GOOD psu, o/c'ing eats volts. The cheap 350W psu that came free with the case ISN'T good enough.

There are basically four things that are affected by overclocking (increasing the FSB);

CPU
RAM
Mobo/Chipset
PCI-e/PCI

The PCI-e/PCI bus needs to be "locked" before you start messing with the others. The freq. that you need are 100/33 (Some boards respond to upping the PCIe bus, Peg-Link does this on Asus motherboards)

You need to find the max FSB for the rest of these individually. Start with the mobo/chipset;

1. Set the CPU at a low multiplier (x5) (If your board supports this)
2. Set RAM to 1:1, and give it ~2.0V

Crank up the FSB by small increments testing with Orthos, running Folding@Home, Seti@Home etc. as well will help. When the Northbridge fails, give it a bit more volts starting at 1.25V, it should now be OK. Carry on until more volts have no effect. Note down the max stable FSB

Now try the max FSB for the RAM;

1. Set the CPU at a low multiplier (x5) (If your board supports this)
2. Set RAM to the ratio that gives the freq closest to its default.

Crank up the FSB by small increments testing with Orthos, running Folding@Home, Seti@Home etc. as well will help. When the RAM fails, give it a bit more volts starting at 2.1V, it should now be OK. Up the FSB until it fails again. Carry on until more volts have no effect. At the same time try relaxing the RAM timings in concert with the volts. This is the most time consuming part of o/c'ing. Note down the max stable FSB. Be careful, too higher voltage will cook the RAM. Some RAM can take over 2.3V most can't, do your homework, find out what chips your RAM uses, this will give some indication of how it will react to higher voltages and tighter timings.

Now try the max FSB for the CPU;

1. Set RAM to 1:1 ratio
3. Set CPU to default multiplier

Crank up the FSB by small increments testing with Orthos, running Folding@Home, Seti@Home etc. as well will help. When the CPU fails, give it a bit more volts starting at 1.3125V, it should now be OK. Up the FSB until it fails again. Carry on until more volts have no effect, best not to exceed 1.5V. Note down the max stable FSB. Multiply it by the multiplier, this is the max freq. that the CPU will run at. Note it down. This will depend on the cooling you have on your CPU. 1.5V with the stock cooler isn't a good idea, for this you'll need a good aftermarket cooler or preferably watercooling.

You will have something like this: (They are made up, your results will vary)

mobo/chipset 430MHz
RAM 1066MHz
CPU 3.4GHz

So from this we can see that you could set this computer to FSB 425MHz, this would give:

RAM 1062MHz at 5:4
CPU 3.4GHz at x8

All mobo/CPU/RAM are different no two will give the same results. My P5B Deluxe/E6600/Patriot PC2 6400 (under 'phase) gave;

mobo/chipset 500+MHz
CPU 4.2GHz (at 1.6V)
RAM 1066MHz (at 2.25V) 5-5-5-15

BE CAREFUL the above can seriously damage you computer. If you don't understand it DON'T do it.