My recently installed Belarc Advisor tells me that my processor is a 1000 Mhz Celeron (1 Ghz). So far so good, but it then says the clock speed on the main ciccuit board is just 100 Mhz. My ignorance of computers knows no bounds, but can this be right? Have I bought a slow machine masquerading behind a faster chip?

The bus speed will always be slower than the chip's clock speed. Basically, the chip's clock speed measures how fast calculations can be done, while the bus speed measures how fast the inputs and outputs of these calculations can travel to other components. 100 MHz is about a fifth of the typical new computer's bus speed, and 1 GHz is about a third of the typical new computer's clock speed (of course there are faster available by both measures).

In some ways it is more important to get a faster bus speed because it cannot be upgraded without replacing the entire motherboard, so I would have opted for a faster bus, but 100 MHz isn't that slow for a 1 GHz processor.

Incidentally, Intel feels that too much attention is paid to the clock speed over other information, including this, so they are pushing for advertising that doesn't use the clock speed.

I have a Amd Athlon 2000 XP+ chip in mine
Is reputed to be as fast as a 2 Gig Pentium
Yet the real speed is 1.7 Gig and the Bus speed is 133mhz
Mind you it's the total sum and setup on the internal components that makes for a fast machine
Not the speed rating
Like qualifying for Pole position in a sick car..can be fast if set up well but mess around with the settings and you are penalised heavily for "time " (adding resource eater programs is typical or not defragging )
My indicator of how fast my computer is going is the Seti screensaver (few 100k big) Which is running at top speed (how do I know?) there is a record of the average time for my account recorded on the Seti site (http://setiathome.ssl.berkeley.edu )and if the average unit time starts rising above 6 hours 35 minutes it means that the computer wants a spring clean and/or defrag

This message has been edited. Last edited by: bedstor,

Thanks. I've had this machine for 2½ years now, but I've only just installed a program that presents these figures virtually next to each other. Subjectively, it seems fast enough, but it did look as though I had been conned.

The Frontside bus (FSB) speed is the speed at which the data is transferred between RAM, AGP and CPU. Many motherboards FSB can be adjusted using either a setting in the BIOS or by changing a jumper switch

100Mhz in a 2½ yo machine is not uncommon,and depends on the RAM installed,

If the label on the RAM states that it is 133MHz, then it is most likely being regulated by the motherboard down to 100Mhz

Bedstor, it appears that you have fallen for the AMD marketing ploy . AMD uses the figure as a comparison with an equivalent Intel processor, so although the AMD Athlon Xp+ 2000 has a clock speed of 1.73Ghz, it works at the same speed as an intel 2Ghz (allegedly).

As I have no benchmarks personally to work with as I always use AMD chips, I cannot vouch for the veracity of their claims

Below is a list of actual clockspeeds depending on FSB for each of the Athlon XP CPUs


Athlon XP 3000+ (Barton) 2.167GHz
Athlon XP 2800+ (Barton) 2.083GHz
Athlon XP 2800+ (333MHz FSB) 2.25GHz
Athlon XP 2700+ (333MHz FSB) 2.167GHz
Athlon XP 2600+ (333MHz FSB) 2.083GHz
Athlon XP 2600+ 2.13GHz
Athlon XP 2500+ (Barton) 1.83GHz
Athlon XP 2400+ 2.00GHz
Athlon XP 2200+ 1.80GHz
Athlon XP 2100+ 1.73GHz
Athlon XP 2000+ 1.67GHz
Athlon XP 1900+ 1.60GHz
Athlon XP 1800+ 1.53GHz
Athlon XP 1700+ 1.47GHz
Athlon XP 1600+ 1.40GHz
Athlon XP 1500+ 1.33GHz