FSB Speeds

pclancy

Having a complete memory gap and trying to settle a debate with someone.....What is a general guide to what FSB speed settings a motherboard should be set at for a processor to run correctly? EG What FSB speed should a P4 2.4 be set at, or a athlon 2200XP? Where do u find that info or what is the rule u use to work it out? Sorry for the stupid question but just cant fecking remember!

CivilServant

Depends on what type of p4 it is. A 2.4b or a 2.4c. B has a fsb of 133 and c 200. Quad pump them and u get 533 and 800 which is where the marketing comes in.

Athlon 2200+ is 1.8Ghz IIRC.

Sir Random

For P4s, these are the fsb speeds for the corresponding cpu bus speeds:
800MHz = fsb 200
533MHz = fsb 133
400MHz = fsb 100

pclancy

is there somewhere u can look up the corresponding FSB speed to a cpu on the web or is there a rule u use to work it out.

OfflerCrocGod

Intels website would be a good place there is no real "rule" as such.....memory speeds are useful to know, wheter it's Quad Pumped or Just DDR.

Sir Random

For P4s, there are only 3 stock fsb speeds to match the 3 different bus speeds.
Different CPU speeds are obtained by using different multipliers:
GHz...FSB..Multiplier
2.0 = 200x10
2.2 = 200x11
2.4 = 200x12
2.6 = 200x13
2.8 = 200x14
3.0 = 200x15
3.2 = 200x16

All the above 800MHz chips have fsb 200. Likewise, all 533 chips have fsb 133 and 400MHz chips use fsb 100. It's only when overclocking that other fsbs are encountered.
Example:
A 2.4GHz/800MHz cpu o/c'd to 250 fsb will have a clock speed of 250x12 = 3000MHz

Woden

similarly for amd chips, they have multipliers of 133, 166 and 200mhz

for example my barton 2500+ is 166mhz FSB with a multiplier of 11

while the 3200+ barton has a 200mhz FSB but again a multiplier of 11.

pclancy

coolaboola. Thanks for the info. Long time since i learnt all that stuff, just couldnt remember!