I can actually add a couple of reasons to Sander's article as to why this is a bad idea.

Processor performance, regardless of MHz rating, doesn't exist in a vacuum. Need an example? Try comparing an Athlon on a KT133 motherboard with a 200 MHz (100 MHz DDR) FSB vs. a KT133A with a 266 MHz (133 MHz DDR) FSB at equal external clock speeds. Try comparing a P4 on an i850 with PC800 RDRAM vs on an i845 with PC133 SDRAM. Try comparing an 1.33 GHz Athlon vs an Athlon XP 1500+ (1.33 GHz external clock) on the same DDR motherboard.

It just doesn't work....especially if you don't take the time to rebrand the rest of your processor line for uniformity. At least then, you've have a relative scale down the line. Of course then you'd run into the issue where the higher end Durons on the Morgan core begin to have better performance than the lower end Athlon.

It gets worse. Should Northwood P4's come out with low end GHz ratings lower than the high end Williamette P4's but have better performance clock for clock, what happens to the relative PR of the Athlon?

The PR number when first used by Cyrix years ago left a bad taste in most users' mouths because of the fact that they grossly exaggerated the performance of the processor. But, while I admire the fact that AMD was pretty conservative in the PR numbers they assigned the Athlon XP's (by all accounts, they could have called the 1.53 GHz part an Athlon XP 2000 based on the benchmarks), this is still a bad idea.

Well, I see 3 kinds of people this rating scheme probably isn't going to work for....

Mr. Knowledgeable: That probably covers most of us here. We often build our own machines, we investigate the parts in minute detail, we look at benchmark performance not branding, a chip’s potential is often more important than the actual shipping speed as a bit of OCing is perhaps on the cards, we’ll continue to call them 1.53GHz instead of 1800+ anyway. Many of these people share Robert’s view that this type of marketing is a bit silly.

Mr Semi-Knowledgeable: He (although it could well be a she, are there any girls out there?) has probably owned a couple of computers so far, he understands what a CPU is and will probably get around to hearing that an Athlon XP 1800+ isn’t actually 1800MHz and will maybe think this bit of ‘insider info’ is good reason to avoid buying one. After all, it’s a bit of a lie isn’t it? AMD are probably trying to con him. All out MHz is where it’s at - IPC is an unfamiliar term.

Mr. Not-So-Knowledgeable: Well, this is the primary target of this whole scheme I’m guessing, and the salesman at Duffo-Computers will be his friend when buying a PC. What will Mr. Salesman say? Well he might tell him an 1800+ is not 1800MHz, but it doesn’t really matter if he does or not. P4s are more expensive, I don’t know if profit margins are higher on them or not, but he may well push Mr. Not-So-Knowledgeable towards the more expensive one anyway (perhaps even for a % commission). But what will he choose? Well AMDs laudable modesty when rating their chips at a maximum of only 1800+ has still left them without a chip that looks as fast as P4 1.9GHz or 2.0GHz, so if he has more money than sense and wants the top model in Duffo-Computers window, he’s still not looking at an Athlon.

So that leaves…..

Strangely, I actually think calling it an Athlon XP is the better piece of cheap marketing, as I’ve already seen people even in hardware forums talking about whether the performance will be lower in Win9x or 2000 as it’s ‘made for WinXP’. If the less informed make a similar connection and of course want Microsoft XP software, this might help reel them in.

Still, we'll see. If it works, it'll be a good move. If it doesn't, I hope it's dropped in time for the Hammer.

You're right, for the most part. But I think there is one major point that you are missing. First, the enthusiast crowd will look at the XP's benchmarks laugh at the marketing BS, and buy one, because it is the fastest thing they can buy, and at less than half the price of Intel's slower chip.

The semi-knowledgeable will act exactly as you have predicted. They will go around whispering that they discovered the secret behind the 1800+ and that it is only a 1533, and what a scam, etc.

But I think you have misjudged the average PC buyer. Mr. Semi-knowledgeable will buy the 2 GHz P4, because it has the big numbers. Most (read: the vast majority of people) look ascance on the 'fastest' and even the second 'fastest' chips on the market, usually with a comment like: "I don't need that kind of performance." While most people really don't know much about computers, they do know a little about buying things in general, and they know enough to stay away from the 'top' of anything, because it always commands a premium.

And about the P ratings in general:
AMD's ratings seem to take into account that the chips may be used in lower-end configurations and compared to machines with better components in them. There is also a suggestion that AMD has taken Northwood performance into account with their ratings.

Since many people expect about a 10% boosts with the Northwwod chip, the 1533 Athlon really would nicely beat a 1800 MHz Northwood, and would probably loose to a 2 GHz one. So AMD might just be front-loading their rating system to take into account that Intel is likely to do something about the horrible IPC of the current P4.

According to this:

http://www.ocworkbench.com/index.stm

(you may need to scroll down), the rating system actually has nothing to do with performance against P4s of any flavour (as I previously thought), but in fact represents speed relative to a TBird. Hmmmm...

As for my previous post, I wasn't trying to suggest that nobody will buy Athlon XPs, I just don't think it will change very much. We'll still buy them because we know they're good, others may still buy them because they offer better value for money, so if they don't want a 'premium' priced product, they may still go for an Athon, but not because of the rating system. AMD haven't really made themselves look any more competetive, because anybody interested in finding out what 1800+ means will probably discover the truth anyway. Most other people won't care if it mean MHz ("whatever one of those id...") or MPH, it will come down to price, or even those adverts on telly with the fantastic little blue men in them. What's AMD's answer to them, huh? That's what they should concentrate on, coming up with their own little mascots, and other such tripe...