Quad Core Thread: Overclocking, Cooling, Motherboards, Troubleshooting & General Info

[nickp8]

Overclocked cpu to 3GHz by increasing FSB to 333. Have left CPU voltage on AUTO. CPU-Z reports voltage is 1.200V on load. Is this too low?

[EarlGrey]

Overclocked cpu to 3GHz by increasing FSB to 333. Have left CPU voltage on AUTO. CPU-Z reports voltage is 1.200V on load. Is this too low?

If it works then it's not too low

generally you want to set as low a voltage as possible, which is probably what your auto setting is doing. Run a Prime95 torture test with 4 threads, and see if it fails. If it fails you may want to go in and up the voltage manually. If there are no errors, then I'd say stick with what you've got

[hse180]

I have just started O/C my Quad and have raised FSB to 350 and set voltage to 1.25 manully and so far is stable ( fingers crossed ) All in all lower voltage is better.

[Kilmatead]

Having learned virtually everything I needed to know about overclocking from Clunk's guide (thanks! ), I still browse the other (million or so) guides that are out there just to see the differing approaches to explaining 'obscure' stuff.

Most of it's all the same (obviously), however being one of the few owners of an extreme processor (the now "ancient" QX6800), this caught my eye:

Just like your CPU, the Northbridge on your motherboard (i865 and newer) has its own internal frequency and latencies which affect overall system stability. This is referred to as the NBCC (North Bridge Core Clock). The NBCC directly affects the performance and stability of your memory and CPU because Intel system used a NB based memory controller.
It has been recently discovered that the NBCC varies with your systems FSB and multiplier settings. The NBCC can be calculated by dividing your CPU current multiplier by its default multiplier and then multiplier the sum by your FSB.

For Example:

E6600 @ 500Mhz and a 7 multiplier:

(9 / 7) x 500 = 642Mhz NBCC

So it can be seen that lowering your multiplier, even though offering addition headway for FSB on the CPU, will increase the NBCC, reduce NB stability and thus cause the overall system stability to decrease.

XE (Extreme Edition) and ES (Engineering Sample) processors have the unique ability to adjust their multipliers up (All XE, not all ES) and down (all chips) while maintaining its multiplier status as default.

For Example:

X6800 @ 500Mhz and a 7 multiplier (just like above)

(7 / 7) x 500 = 500Mhz NBCC

As you can see, the X6800 has the exact same settings as the E6600, however, the NBCC is lower, resulting in increased system stability.

(The full guide is at Intel Guide for those interested.)

I'm wondering if this claim of his (he seems to know what he's on about) has any merit? I've never heard any mention of this "special" ability of extreme processors to "retain" their default multiplier status even if the multi is changed up or down? I "kind of" understand what he's saying, but is it true or just waffle? Most people are happy enough to just say the only difference between regular and extreme chips is the ability to up the multi. Is there more to it?

[mrk]

I have just started O/C my Quad and have raised FSB to 350 and set voltage to 1.25 manully and so far is stable ( fingers crossed ) All in all lower voltage is better.

Mate is the 1.25 you set the VID too ? Mine is 1.325 according to coretemp so I'm tempted to manually adjust the vcore to that at 350