- Introduction

Last year, Advanced Micro Devices introduced us to the first two Athlon 64-bit processors. The Athlon 3000+ and FX-51 were built for 754 and 940-pin sockets respectively. Now AMD once again changed its CPU design and came up with a new socket infrastructure, the 939-pin socket, which seems to be the future of the Athlon 64 processors with its main competitor being the S-940.

The 939 socket processors offer the same class performance as the 940-pin but with less cost for the motherboard manufacturers since it only requires a 4-layer PCB, compared to the 7-9 layer requirement of the previous generation.

However, the most important difference might be the fact that the 939 no longer requires registered RAM modules. Registered RAM uses some registers or buffers that intercept the data transfer and delay it for one clock cycle to make sure that all data is error free and transferred successfully. Registered DIMMs are basically designed for servers and systems where data integrity is a primary issue. This is why the 940-pin FX processors are often characterized as being designed for workstation computers.

Socket 939	Socket 940

So with registered RAM being more expensive than unbuffered RAM, S-939 makes a cost-effective solution, convenient for gaming and personal computers.

Let's take a look at the following table showing all the AMD 64-bit Athlon processors and some of their major differences.

As you can see, the 939-pin socket seems to take over the S-754 and S-940 on both Athlon 64 and Athlon FX families.

Athlon 64 processor architecture

In this review, we had the opportunity to test the 3800+, the latest and very promising platform in the Athlon 64 family by AMD.