what is fsb ? 1

[hellbeach]

Hello everyone
I just bought a MSI 865GVM2-LS and a P4 3.0 with 800 MHz FSB.
My question is: Where can I set the 800 MHz FSB ? When I check in BIOS I can only set a max of 233 MHz.
Am I missing something ? Will the sum of ths FSB be higher since the processor has multithreading ?

 

[pcrtech]

hellbeach

Not sure where your getting 233MHZ FSB checked out the specs below and it Supports FSB *400 (Northwood only)/533/800 MHz. Did the mobo come with a cd? I would try installing the software and run setup.

http://www.firingsquad.com/products/hwproduct.asp/4367?viewdesc=1

pcrtech

 

[cdogg]

P4 FSB's are quad-pumped internally. There is no setting. If you have the appropriate memory in the system, your FSB should be running at 200MHz (200 x 4 = 800).

If the CPU clock speed registers correctly in the BIOS, then you know the FSB is set correctly since it's directly related.

There are a ton of threads at this site discussing this in the past. Also, I'm sure a google search on "frontside bus", "P4", "BIOS" and "800MHz" will turn up a lot of useful information.


~cdogg
[tab]"All paid jobs absorb and degrade the mind";
[tab][tab]- Aristotle
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[hellbeach]

cdogg: That´s what I suspected, that it was "quad-pumped" internally. Thanks for clearing that up for me.

/D

 

[dakota81]

The issue you have to sort out is "what is quad-pumped"? It is NOT the clock speed that's quad-pumped in any way even though that is how intel gets their 800fsb number. AMD does the same thing with their double data rate.

It is the data path between the cpu & chipset that is 128bits wide instead of the 32bits in the P!!! architecture - this is what is "quad-pumped".

I mean really, "200MHz, 128bit pathway" doesn't quite sound as awesome as "800fsb"!!! Because after all, 800 > 200 > 128, and you know the higher numbers ALWAYS mean faster machines. =)

 

[cdogg]

Dakota brings up a good point. Although it wasn't asked, the way "quad-pumped" works is by widening the path in which data can flow.

A good analogy is expanding a 2-lane highway into 8 lanes. The speed limit stays the same (200MHz), but the amount of traffic that can pass in that amount of time is essentially multiplied by four ("quad-pumped").

The analysis is a bit different though. At heavy usage times, the extra 6 lanes pays off. But when traffic is normal or low, then the extra bandwidth doesn't amount to much due to that speed limit of 200MHz.

So for the occasional rush hour, it performs like an 800MHz FSB champ! But for everything else, it's probably averaging somewhere around a 300MHz contender. Due to the complexity involved in getting the main bus to run at very high speeds, it might be some time before we see true 400MHz or beyond.


~cdogg
[tab]"All paid jobs absorb and degrade the mind";
[tab][tab]- Aristotle
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[hellbeach]

ok, tnx for the excellent explanation guys.

/D