How to calculate AMD XP+ speed ratings in MHz

I recently received a question from a fellow Infopackets Reader, R. Barnes. He writes:

" Great newsletter as always. I was wondering if you could explain the new AMD processor speed ratings. I've seen them in mail order catalog and TV, but haven't heard an explanation of their '2200+' statements. I would assume that it is indeed the speed of their processor but how are they in relationship with say a 1.2 GHz Athlon processor, or even a Pentium 4 1.3GHz? "

That's a good question.

The speed rating that AMD is using for its new line of XP processors represents their new "QuantiSpeed" architecture. Basically, it's a word that AMD made up to impress you. From the AMD website, QuantiSpeed architecture "allows the AMD Athlon XP processor to accomplish more instructions per [CPU] clock cycle." Yippee! Still confused?

Yeah, well -- all you really need to know is that AMD is trying to change the minds of how people look at MHz ratings. If you didn't already know, MHz simply stands for Megahertz (another unit of measurement). Up until QuantiSpeed was introduced, many users were accustomed to rating the speed of a computer by its raw MHz number.

That doesn't hold true these days. That's why the QuantiSpeed rating was introduced.

Besides that, the word QuantiSpeed sounds cool.

I mean, there is a way to calculate the pure MHz rating of an XP processor, and I will show you how to do that. But before I get into that, there's something you should know. Basically, there are a few things to consider when comparing dissimilar systems with MHz ratings.

• The FSB rating of the processorFSB (front side bus) is how fast the processor communicates with other peripherals inside the computer. Faster FSB = better.

 
• The type of RAM used with the processor The new generation of Intel Celeron processors are still using 100 MHz SDRAM. That's an old type of RAM and it isn't very fast, compared to RDR RAM (some Pentium 4's) and DDR RAM (AMD Athlon).

Pentium 4 systems using RDR RAM are expensive for two reasons.

1. Dollar for dollar, Pentium 4 processors are over-priced compared to an AMD Athlon. There's lots of information on the Internet that proves this.

 
2. RDR RAM is made by RAMBUS. I remember reading somewhere that they hold the patent on its design and that's part of the reason why it's so bloody expensive. I might be wrong about this.

Ok, so how do you calculate AMD XP ratings?

If you remember how to "solve for x" using High School math, then we can solve the question about AMD's mythical MHz madness. In this case, the variable X can represent the MHz rating using the generic formula "MHz = (XP rating/1.5) + (500/1.5)".

Using the 1800+ processor QuantiSpeed rating, we have:

• MHz = (1800+/1.5) + (500/1.5)
• MHz = 1200 + ~333.33333333...
• MHz = ~1533.33

So, there you have it. By the way, the squiggly ~ means "approximately." Since .333 is infinitely repeated, it's just nice way to represent "short form."