characteristics of different fsb speeds

[ZION]

What effect does different fsb speeds have on the overall performance of an audio computer. what characteristics would you look for when changing from one to the next.

[maggotcontrol]

It's quite simple. The higher the FSB, the fatter the pipe. (to put it in simple words)

Comparison:

133MHz FSB & 11x multiplier = 1.46GHz
166MHz FSB & 9x multiplier = 1.49GHz

Both resulting CPU speeds are close to 1.5GHz or the equivalent of an Athlon XP 1700+ processor.

Because of the fatter pipe removing quite a bit of the bottleneck between the CPU and memory, you'll notice that the higher FSB allows you to run a few more plugins and better stability at low latency - Stability as in less dropouts and a more responsive GUI as the CPU meter reaches 90% and up. Similiar to how a dual CPU would feel although less drastic - A project that would feel jerky and with occassional dropouts would play smoothly with a higher FSB.
Hope this answers your question.

yoshi
www.studiokobari.com (http://www.studiokobari.com)

[the_lost]

MC, where are you deriving the multiplier? Where's it come from?

jay

[maggotcontrol]

Sorry for the late resonce (very busy here building a few systems).

The multiplier is another setting in the BIOS in addition to the FSB that determines the actual CPU speed. (MHz, GHz etc.)
It's the number that you multiply by the FSB to achieve it's rated speed.

IE: Athlon XP 1700+ is a 1.47GHz processor running on a 133MHz FSB.
1.47GHz = 1470MHz.
multiplier x 133 = 1470
1470 / 133 = multiplier
multiplier = 11.05 or 11 as set in the BIOS.

The interesting thing is, as you set the multiplier lower and increase the FSB, you can still achieve 1.47GHz or close to it. Thus effectively overclocks the FSB and memory (if in sync)

IE: 9 x 166 = 1.49GHz
FSB is overclocked by 33MHz. (166-133)

This yields in better performance than increasing the multiplier and lowering the FSB....as the FSB is the real limiting bottleneck here.

With the proper knowledge and hardware configuration, you can easily take an Athlon XP Thoroughbred and push beyond 200MHz FSB.

Hope this makes sense.

-Yoshi
www.studiokobari.com (http://www.studiokobari.com)

[This message has been edited by maggotcontrol (edited 05-09-2003).]

[Bops2000]

What is fsb ?
front side buss speed? like setting the north bridge?
Ignore me I just curious.

[maggotcontrol]

The FSB (front side bus) is the bus or path where information travels between the processor and memory. The faster this is, the quicker the processor can store and retrieve data from RAM. It is often the biggest bottleneck in a high clockspeed CPU system. Kind of like having a slow middleman.

Yoshi
www.studiokobari.com (http://www.studiokobari.com)