Does FSB depend on CPU?

[winglesslight]

Hi
What is Front Side Bus?
Is it bus on the motherboard or bus in the CPU?
I have PC100 RAM so if I buy Mobo with FSB 133 will it work backward?
Or do you suggest safely go for FSB 100?

Thank you very much.

 

[jiffy]

What kind of mobo do u have? If you have the manual it will tell you if it supports 133 or not.

 

[camieabz]

It is the speed in MHz at which the motherboard, CPU, and RAM operate.

PC100 RAM is designed for a motherboard that runs at 100MHz. etc. etc.

Your CPU speed is calulated by taking your FSB and the multiplyer. FSB = 133MHz Multiplyer =7.5 CPU Speed = 1000MHz.

You can use faster memory in a slower motherboard. That is to say PC-133 in a PC-100 system, but it will only run at the FSB setting. Slower memory in a faster motherboard isn't recommended unless it is quality memory (like Crucial or similar).

On Pentium chips the multiplyer is locked. A 1000MHz PIII has its multiplyer locked at 7.5, so you can only alter the FSB to change the CPU speed. This can mean problems which you don't want to know about right now. AMD chips' multiplyers arn't locked, so they are more flexible with options, but therefore can be more unstable if not correctly configured.

DDR memory is still 100 or 133 FSB, but it is double pumped to give the 200MHz or 266MHZ reported.

Try this <A HREF="http://www6.tomshardware.com/mainboard/97q1/970101-1/" target="_new">link</A> for a selction of older chipsets and their FSBs.

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[winglesslight]

I don't have doc of mobo.

I gotcha.
Thank you very much for kind and concise explanation.
So FSB is the only bus I need to know to choose RAM.
So You have to choose mobo with certain FSB for Pentium.
Since I have Pentium III 450Mhz, I can buy only mobo with 100FSB, not 133FSB.
Is this right?

 

[camieabz]

You could buy a mobo with 133Mhz, and either upgrade later or try overclocking your CPU by raising the FSB.

Not recommended if you're a novice though. Maybe Crashman could add to this. He's got more oc'ing experience than me.

Otherwise, your CPU will run at 100MHz on 133 mobo.You may be able to have more options then for faster HDDs faster memory etc.

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[camieabz]

You could buy a mobo with 133Mhz, and either upgrade later or try overclocking your CPU by raising the FSB.

Not recommended if you're a novice though. Maybe Crashman could add to this. He's got more oc'ing experience than me.

Otherwise, your CPU will run at 100MHz on 133 mobo.You may be able to have more options then for faster HDDs faster memory etc.

<b><font color=blue>~scribble~</font color=blue></b> <A HREF="http://www.ud.com/home.htm" target="_new">Help cure cancer.</A>

 

[Crashman]

You can get a board with either 100MHz or 133MHz FSB. The FSB will run at whatever you set it at, 133 capable motherboards will run at 100 if set that way. Since both your CPU and Memory have a 100MHz bus speed, you'll be running at 100.

What's the frequency, Kenneth?