AMD Socket 939 4000+ and FX55

Review by Jason Jacobs on 10/19/04
Processor Provided by AMD

Socket 939 FX55

It is the practice of AMD that there is only one FX processor manufactured at a time. This means that when the FX53 came out the FX51 was discontinued, and now that the FX55 has been launched the FX53 will no longer be made. Aside from that the FX series also has the distinction of being the only AMD processors that come with multipliers that are unlocked. The Athlon 64 may have its multiplier lowered, but only the FX series consumers can raise the multiplier. Don't worry TWL took the FX55 for a spin and we do bring you over clocking results.

The FX55 uses much the same architecture as others in the 939 line with the following note from AMD:

"A technology that has been used to increase performance for FX-55 is strained silicon-on-insulator. As you may know, strained silicon involves
modifying the electrical properties of transistors in order to increase
their performance. While there are varying ways of achieving transistor
strain, the result is usually similar... the atomic structure of the transistor
electrical path is strained into better alignment, which allows for improved electrical flow.

"Strained silicon continues to be an active area of R&D and the
techniques we have implemented in the Athlon 64 FX-55 processor are one
manifestation of a series of strain technologies in development with our
partners. We expect this work to provide even greater enhancement of
performance as techniques for introducing strain are further improved
and refined. We will disclose the details of this strain technology
jointly with our partners in the future."

It looks as though AMD is continuing its tradition of technology enhancements including revisions, stepping's, and stepping modifications even within the same lineup. Here is how CPUZ sees the FX55 with Cool N' Quiet Enabled:

At a remarkable 1.07 Vcore the FX55 can trade punches with the top Pentium 4 and still keep its cool. The wonderful benefit of Cool N' Quiet.

PRICING:
AMD Athlon 64 FX-55 processor $827 each (PIB)

As you can see the FX55 receives a healthy 200Mhz speed bump over the 4000+ in addition to being multiplier unlocked. We took a look at how the FX55 performed in an over clocked as well as stock condition to see if this top end CPU is really worth the high price tag.

AMD FX55 Performance