Help on GTL, clock skews, etc

[tonyluu]

GTL & clock skew settings should only be tampered with especially on overclocking quad core processores with high FSBs, correct?

For CPUs with low FSB walls such as the E5x00 series, you shouldn't have to worry about these right?

Or you should start configuring these options when you get close to the CPUs FSB wall or one in general (450FSB+)

How do you know for certain when a board needs a bit of MCH vCore adjustment?

What about other termination & reference voltages?

I

 

[Zero82z]

The simple answer is that there's really no way to know what settings you have to tweak aside from simply playing with them and seeing what helps. Every board and every CPU is different, so there's no one size fits all method to configure your settings to hit a certain speed.

 

[BillParrish]

MCH Vcore should be increased when you start to see memtest failures with known good memory during FSB increases.

I agree with your statements about GTL and skew settings. A last resort at high FSB when additional MCH voltage (or have reached the limit of comfortable Voltage increase) is no longer effective. It is unusual to get much more FSB even if you find the "magic" mix of settings and I would try just a touch of GTL increase first, then skew. Actually I likely would not bother with skew at all.


Concerning the other termination and reference voltages they are what they say they are, reference voltages the cpu and mch use to set internal voltage levels. Usually not needed to be messed with. At most I would try "one notch" of increased reference voltage for stablity at high FSB but would not be looking for that increase to give me more FSB. Termination voltages like the GTL mess with the voltage level that defines a vaild data bit on the buss and I would use as a last resort in finding stablity at a high FSB not more FSB.


I used "I" throughout this post meaning "its what I do", "it is my opinion" etc. There are certainly other schools of thought out there and I want to disclose that when building P45 boards (mainly Gigabyte) I seldom if ever need to do anything but raise the MCH voltage and set the memory voltage and timing to get a decent mid-range OC. As these are customer board I am not going for the "bleeding edge" they must be stable. If you want every last possible MHz of FSB these settings can help but in my experience thay usually add more of a confusion factor until you understand exactly what each one does and have a plan for attacking the OC and keep notes like your life depended on it while doing extensive testing. A huge time sink.