How To Tell Hammers Apart

A few folks asked about another mysterious processor that has shown up on Newegg’s roster.

What is it?

We’ll answer that in the course of this article, but given the increased interest in these processors along with what seems to be new ones popping up every day, we’ll tell you how to identify Hammer processors by their codes so you end up with the right one.

Unfortunately, AMD has not yet updated its tech docs to describe these new processors, but there’s enough information in the current ones that combined with a little observation is enough to be able to identify any Hammer you might want to buy.

(Most of the information used in this article can be found in this AMD techdoc.)

The Identifiers

The way you identify Hammers is by the codes in the Ordering Part Number (OPN):

In the case of this mysterious 3400+, the OPN is:


We’ll break down each element of the code, and show you what it means.

The first position of the code:


says what type of processor this is.

The codes for this position are:

A = Athlon 64/FX
O = Opteron
S = Sempron

(To keep this article as simple as possible, we’re going to leave out detailed explanations on Opteron codes. See here, pages 6 and 7 for explanations of Opteron codes.)

In our example, this is an Athlon 64 (or FX) type of processor.

Processors from the Athlon generation also start with the letter “A.” but Athlon processors that start with the letter “A” have either two or four letters at the beginning of the code, never three.

(We also note that all Sempron processors use the identifier “SDA,” whether they’re Hammer generation or socket A processors. The way you tell them apart is by the PR rating. If it’s 3100 or more, it’s a Hammer, below 3100, it’s a socket A.)

The second position of the code:


says what computing environment the processor is meant to be in.

The codes for this position are:

D = Desktop
M = Mobile
S = Server

In our example, this is a desktop processor.

The third position of the code:


says whether the CPU is a regular or low-wattage processor.

The codes for this position are:

A = Desktop replacement (regular wattage)
N = 62 watt processor
D = 35 watt processor

In our case, we have a regular wattage CPU.

The next items you’ll see will be either four digits, the letters FX followed by two numbers, or three digits.


If it’s the first, it’s an Athlon64 or Sempron (but you already know that from the first letter).

If it’s the second, it’s an FX.

If it’s the third, it’s an Opteron.

In our example, we see four digits, so it’s an Athlon 64 or Sempron, but we already know it’s a 64. We know it has a PR rating of 3400.

No, there is no clue from the PR rating what socket the processor uses, or whether it’s a 90nm or 130nm, other codes will tell you that. CPUs with the same PR rating can run at different speeds and/or have different size caches, too. There is a code that will indicate processor size, but there is no code that gives you the actual frequency of the processor.

In the future, we’ll come up with that, but frankly, we don’t know at exactly what speed our example runs. It shouldn’t be 2.2Ghz, since AMD already calls a CPU running at that speed with 512K cache a 3500+. It shouldn’t be a 2GHz, since there’s already the equivalent out there rated at 3200+. It may well be a 2.1GHz, except that AMD hasn’t made a Hammer yet with a fractional multiplier (i.e. 10.5 rather than 10 or 11). It might be a 2GHz processor with 1Mb cache, except that Newegg doesn’t call it that (they could be mistaken, no doubt they’re as confused as the rest of us).

Codes Completed…

After the three or four numeric or alphanumeric series, we get another letter:


This tells you what socket the processor uses.

The codes for this position are:

A = socket 754
C = socket 940
D = socket 939

In our example, this is a socket 939 processor.

The next position:


tells you what voltage the processor uses. This position is very important because this is one way you can tell between a 90nm and a 130nm processor.

The codes for this position are:

E = 1.5V
I = 1.4V
Q = 1.2V

If the code says, “E” it’s a 130nm processor. If it says “I” it’s either a 90nm desktop processor or a 130nm mobile processor. If it’s a “Q,” it’s a mobile processor.

In our example, this CPU is a 1.5V processor, and therefore a 130nm CPU.

The next letter:


tells you the maximum die temperature of the CPU.

The available codes are:

K = ???
O = 69C
P = 70C
X = 95C

We don’t know what “K” stands for, since AMD hasn’t told us yet. However, “K” has been used for all 90nm processors we’ve seen so far. “O” stands for some Opterons. “P” is the standard for 130nm desktop processors, and “X” is a standard for mobile processors.

In our example, this CPU has a maximum die temp of 70C and thus is a 130nm desktop processor.

The next position holds a number:


which tells you how much cache the processor has.

The available codes are:

2 = 128K
3 = 256K
4 = 512K
5 = 1Mb

“2” is only used by some Sempron mobiles. “3” is used by all other Hammer-based Semprons. “4” stands for Newcastle/Winchester-based Athlon 64s. “5” stands for Clawhammer-based A64s, FXs, and Opterons.

Last but not least, the code ends with a two-letter code:


which tells us what stepping the processor has.

The current codes for 130nm processors (excluding Opterons) are:

AP = A64, A64Mob, C0
AR = A64, A64Mob, CG


AW = A64, CG
AX = A64, A64Mob, Semp, CG


We also know that all 90nm CPUs we’ve seen so far have a stepping code of “BI.” This indicates that this and future steppings of 90nm processors will start with a “B.”

This helps us quite a bit with our example, because it has a code of “AZ” and there is no “AZ” code listed in the AMD tech docs. We can tell that it’s a 130nm processors, and that it probably is another CG stepping.

That’s it for now. No doubt this will get updated often in the weeks to months ahead.


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