My Inquisitive Nature :)

[Dave_07]

Do fsb speeds make a difference ? eg a topline AMD cpu (AthFX, Any Skt A 3200) may have about 200-400fsb but a p4 has 533 or 800fsb, but alot of people say the new amd's are noticeably quicker, but they have lower fsbs then p4's ??
In the big picture, it looks like fsb dosen't make much of a den't on speeds.
However I would have thought that the fsb would be the most crucial part tho, as it's basicaly the speed at which the cpu communicates with the mobo, and no matter how fast the cpu may be if the speed at which it talks with the mobo is too slow, then isn't that gonna bottleneck the info >to cpu> back to you speeds ? lol sorry don't know the technical term

Dave.

[Steve]

FSB is very important as it's the speed at which the CPU communicates with the motherboard - for example if memory speed is synched with fsb you get optimal performance in most cases.

It's worth noting that AMD's use DDR (dual data rate) and Intels use QDR (Quad Data Rate.) So a 200mhz FSB in DDR is 400mhz, QDR 800mhz. The whole QDR DDR thing isn't as simple as it sounds though.

[SilentDeath]

they dont make much differnce.. but p4's need much higher fsb for better performace because of the arcitecture (sp?). p4's do a lot less per clock so id imagine they are happy with less bandwidth but they need high fsb so there not constantly waiting for data.. (think of this like waiting for a bus, having buses that can carry 2x more ppl, or twice as often?)
p4s also benifit lot from huuuge cache iirc, where as doesnt make too much difference for amd chips (double cache - bartons, perform about as good as a tbred clocked 200mhz faster)
past 200fsb for amd doesnt make much differnce

[Dave_07]

Arrrr, so Intel's have a lesser degree of arcitecture than amd, and so need higher fsb's to keep up with amd.
So an example where fsb come's into play is in the arcitecture quality of the cpu. So, I guess you could say that fsb levels are a mesure of cpu arcitecture quality. Good.

[Stoo]

Well, it's a bit more complicated than that, but it's close enough without delving into the depths of processor design

[Flymo]

FSB speeds can only REALLY be compared whent running the same type of CPU.
Changing my XP 2400+ from 133(266) FSB to 200(400) FSB, whilst dropping the multiplier to 10 so as to keep the same clock speed (2.0 GHz) resultes in an approximate 10% increase in benchmark results (sandra and 3D Mark 2001).


Flymo

[unrealrocks]

This is where the rating which will be used on most CPUs next year ... where it rates the work done per certain time (can't remember what its called, someone help me out here, lol) ... this'll mean CPUs can be directly compared - end speed anyways, and things like FSB and clock speed will simply be on the specs sheet!