Advanced Frequency Settings in BIOS

[forumjoe]

Board is P55-US3L, BIOS is v.FH. I guess most of this will apply to other P55 boards.

Included in the Advanced Frequency Settings section of MIT, in the BIOS, are these settings:-

CPU Clock Drive (adjustable in steps from 700mV - 1V)
PCI EXpress Clock Drive (adjustable in steps from 700mV - 1V)
CPU Clock Skew (adjustable from 0 psec upwards)

How can one know the values to which to set these?

I've currently got the first two set at their default values. Initially, I had the clock skew set at zero but currently I've pushed it up to 50 psecs, thinking that otherwise jitter between the CPU and chipset clocks could result in iffy operation. But, without using an oscilloscope, I can't see how one can possibly know what the default timing relationship is between them, or indeed even know what the acceptable tolerance is.

Incidentally, my BIOS is suffering from the ubiquitous 'CPU core temperature bug'. I hope GGTS will soon find a better workaround for this than the one we're all having to use at present. I'm also getting strange random accesses to the FDD (empty) in this new PC, though the accesses stop after the PC's been on for some time. (And no, it's not that it's the first boot device in the BIOS menu). Seems to be mouse-related. And the HDD activity LED on my PC's casing is showing a very regular, constant access, even at idle. Never experienced that on any PC I've ever had before. Anyone else observing similar things on their P55 machine? I accept, of course, that these sorts of things can be due to features within certain applications, so may possibly have no cause in the board itself or in its BIOS.

[Lsdmeasap]

IN regards to your HDD LED activity, do you have DES installed?  If so disable or uninstall it and see if that stops what you are seeing.

Really though, even when idle, windows is ALWAYS accessing (Read and write) the hard drives, for various background tasks and data collection for performance counters.

Those should always be at the BIOS optimized defaults, the only time you need to change them would be at super high overclocks

CPU Clock Drive >>>>>>>>>> 800
PCI EXpress Clock Drive  >>>>>>>>>> 900
CPU Clock Skew  >>>>>> 0ps

[forumjoe]

What is DES?

Yes, I've appreciated that background services run in Windows even when the machine is at idle, but I've never noticed this absolutely incessant HDD activity on any other PC I've ever had. Read or write accesses are apparently being made about every three-quarters of a second. If the HDD is truly performing these accesses, then the poor old read/write armature of the HDD will be working its socks off, and I'd wager that the HDD wouldn't last very long. Just count the numbers of seconds that your machine's on for in, say, a week!

I've been wondering whether a service of some kind in Windows is regularly polling hardware devices on my machine, as one of the other remaining bugs I have is that I'm getting random accesses to the FDD. (This P55 board has an interface for a FDD, which I'm using). I'm pretty sure it's not caused by a virus; I've been absolutely meticulous about firewalling and antivirus.


Postscript: By DES, do you mean Dynamic Energy Saver? If so, Im not using that at all.

[Dark Mantis]

Yes Lsdmeasap was asking about Dynamic Energy Saver. If you are not running it then obviously it has no bearing on your problem.