AMD
Processors by AMD continue to use the same performance rating system that compares them to the old style clock speed product names of Intel processors. AMD's performance ratings do at first seem simpler, but the actual product features underlying the rating numbers can vary in a confusing way. Better still, AMD's Opteron chips use a numbering system similar to Intel's, although given that it isn't used on quite as many products, it's a little easier to understand. For this article we're going to focus only on desktop/mobile chips.
There are currently two main desktop product ranges made by AMD, Athlon 64 and Sempron. The PR system started life with the older 32-bit Athlons and continues to be used with AMD's latest 64-bit Athlons. In the mobile market, we have mobile variants of the Athlon 64 and Sempron, along with Turion 64. Let's leave out the mobile processors for the time being, however.
Where the four figure PR number is used, it tends to signify performance equivalent to the MHz clock of an Intel counterpart, with a '+' at the end of the product number to hint that the performance is in fact greater. So, the higher the number, the higher the performance. Alas, clock speed isn't the only thing that influences product number.
There are currently two socket types available for Athlon 64 processors, socket 754 and 939. As such there are two Athlon 64 3000+ processors currently being produced, one for each socket. The Athlon 64 3000+ for socket 754 runs at 2.0GHz, whereas the Athlon 64 3000+ for socket 939 runs at 1.8GHz. How can that be? Well, the latter processor has support for dual channel DDR memory, which will boost overall performance to something like that of the socket 754 3000+, despite the clock speed difference.
There are also different cores available for the same brand of processor. For example, we've seen clawhammer, newcastle, winchester, venice and san diego cores for Athlon 64. A change in core will likely influence the model number that processor gets, particularly if the amount of cache changes, or new features are added.
Until now, I've left out some of the sub-types of Athlon 64. Yes, it does get a little more confusing, but not a great deal. Here are two other processor ranges you'll find under the “Athlon 64” umbrella.
Athlon 64 X2 – These are dual core Athlon 64 processors. Their product codes work just like other Athlon 64's, greater numbers signifying greater performance. Of course, as there are two processing units on the chip, the way the code is worked out changes.
Athlon 64 FX – AMD's answer to the Intel Extreme Edition CPU, these processors are high performance, high price parts, which don't use the 'classic' model number system, instead using a two digit suffix, a greater number signifying a faster part. For example, an Athlon 64 FX-53 is slower than an Athlon 64 FX-55.
So what about Sempron? Well, the bigger the number, the greater the performance, but as with the Athlon 64, clock speed isn't the only thing affecting a product number.
How about mobile? You'll be able to identify a mobile Athlon 64 or Sempron because the product name starts with 'Mobile'. That couldn't be any simpler, could it? Again, performance rating numbers are used. Turion 64 mobile processors work differently, with two letters and two numbers making up the product identification. The letters signify the processor class, and as the second letter increases, the 'mobility' of the processor increases too. What that means is the later in the alphabet the second letter is, the better the power consumption, heat output, etc. is. The two digits increase to represent performance. A bigger number equals more performance. So, a Turion 64 ML-37 is quicker, but less 'mobile' than an MT-32.
I have to remember all that?
If you've got this far and feel like crying (I did), don't worry. Both AMD and Intel have to make a lot of decisions to create a product number that fits in correctly with the products around it. That can, when you line up all the processors together, make things seem a little confusing. However, when you break things down it gets easier.
Find the product range you want. Within that range, the higher numbers will signify better overall performance. Comparing across ranges can be tricky at times, but it's important to remember that you're not alone. If you're trying to decide which processor to buy, be on the look out for reviews and also seek the opinions of users on forums, who will be able to tell you specific things like which processor core is preferable. Of course, you can also refer to the manufacturer's website, where processor models within particular ranges are compared side by side, so that you can see which model fits where, and what features it has.
