my minds gone blank, fsb

[Party.Ryan]

some please explain how upping the fsb/multiplier will make the agp, pci etc run faster

[Party.Ryan]

i remember now, is it fsb
shared by shared by 4 - AGP
shared by 2 - PCI


??

[Enverex]

Depends on the multiplyer that the motherboard is using. Some have it locked so nothing changes when you increase the FSB, and others use deviders, so that when it reaches 166 (from 133) it hits the next devider and the PCI bus goes back to normal.

So at 133mhz FSB the PCI bus is the FSB / 4 (33mhz) and the AGP bus is the PCI * 2 (66mhz).

NS

[Austin]

Modern P4 and nF2 Skt mobos impliment a PCI/AGP lock. Older mobos use a divider of the FSB in order to derive the speeds. It's largely the divider which dictates what FSB a given mobo can use. For instance KT400 were designed for 333FSB (2x166mhz) so used a 1/5 divider (PCI=33mhz while 1xAGP is double that). KT600 are designed for 400FSB (2x200mhz) so use a 1/6 divider. They support lower dividers for the lower FSB too of course, it is usually an automatic thing rather than user selectable. The problem with dividers is when you try to run at unusual FSB speed, such as 380FSB (2x190mhz) on KT400 where PCI is 190/5=38mhz and hence 1xAGP=76mhz (4xAGP=304mhz and AGP8x=608mhz). It's considered within PCI spec to range from 30mhz to 36mhz although some devices are more sensitive/picky than others. You may also find things like IDE are derived form the PCI speed and as such you can experience HD corruption past a certain speed. All things to bear in mind when o/c'ing divider based mobos esp when you are dealing with a locked CPU (or where your mobo's max multiplier is insufficient).

[Party.Ryan]

the manual dont have these details in there and i have found an area were you can set the agp Mhz
so i've left that@66 atm...

when i get a chance ill look into how my board works,

cheers ears

[Vijay]

Where in the Bios did you find this setting ?

Vijay