Ratio of Sytem Bus to processor core frequency

[Nathan Detroit]

While reading Pentium II Processor Developer's Manual (http://developer.intel.com/design/PentiumII/manuals/24350201.pdf) I found a chart much like the one you use to change what voltage a slot P2/P3 asks for from the mobo, except it's entitled System Bus Clock and Processor Clocking. It has 2 settings for safe power on, and 3 others, which are: 1/4, 2/7, 2/9. This can be found on Pp 83 of this document.

Meaning of this, anyone?

[Pinky]

Nathan Detroit (Jun 26, 2001 09:48 p.m.):
...entitled System Bus Clock and Processor Clocking. It has 2 settings for safe power on, and 3 others, which are: 1/4, 2/7, 2/9. This can be found on Pp 83 of this document.

Meaning of this, anyone?

You're dividing the bus speed by that figure in order to keep the PCI (sound, modem, etc) bus within its specifications (as close to 33 as possible). My bus clock multiplier is 1/3 since I'm at 100 Mhz, this gives me a 33.33333 Mhz PCI bus, so my cards operate within spec.

[Nathan Detroit]

Ok I thought so, so assuming I can if I run at 153 FSB and set this to 9/2 then my system bus will run at 34 instead of 51 or 38.5 ( depending on the mobo)? I have this correct?

[Kingslayer]

Wow I wish I had those settings.....

Im at a 167 Mhz FSB. With a 1/4 divider. That means I'm running at almost a 42 Mhz FSB. That translates into...IM SUPRISED IT'S RUNNING!

[Pinky]

Nathan Detroit (Jun 27, 2001 08:18 p.m.):
Ok I thought so, so assuming I can if I run at 153 FSB and set this to 9/2 then my system bus will run at 34 instead of 51 or 38.5 ( depending on the mobo)? I have this correct?

Yes, exactly. I wish they kept those dividers in modern boards, oh the havoc I could cause!!

[Nathan Detroit]

Pinky (Jun 27, 2001 08:41 p.m.):
Yes, exactly. I wish they kept those dividers in modern boards, oh the havoc I could cause!!

?!
Your Celeron 366s can't do this, this was taken from an intel technical document for PII's, I don't understand your statement...

[Pinky]

Nathan Detroit (Jun 27, 2001 11:38 p.m.):
Pinky (Jun 27, 2001 08:41 p.m.):
Yes, exactly. I wish they kept those dividers in modern boards, oh the havoc I could cause!!

?!
Your Celeron 366s can't do this, this was taken from an intel technical document for PII's, I don't understand your statement...

The other systems I have, a P3 for example, would benefit when overclcocking by having these options... I only mean that it would be fun to play with on modern chips, not a technically correct statement... merely for funsies, like red ink for pens, or bumper license plates for bicycles.