AMD Athlon 64 FX-55 & Athlon 64 4000+

Introduction & Specifications

Almost five months have passed since AMD and Intel released new flagship processors.  Back in June, AMD launched its Athlon 64 FX-53 and Athlon 64 3800+ processors, and Intel officially took the wraps off of its LGA775 platform and the 3.6GHz Pentium 4 560, along with a few lower-speed processors and a pair of supporting chipsets.  Now, a few months later, with the holiday season rapidly approaching, it only seems logical that both companies would up the ante again to entice holiday shoppers to upgrade.  AMD shows its hand first with the release of two new high-end processors, namely the Athlon 64 FX-55 and the Athlon 64 4000+.

The Athlon 64 FX-55 is a 2.6GHz (2600MHz) processor that incorporates all of the features and technology that have made the K8 a success, along with a few enhancements.  The Athlon 64 4000+ is a 2.4GHz (2400MHz) part that is basically a relabeled FX-53.  We took both of these new processors for a spin to see just how well they performed against AMD's previous high-end processors. We benchmarked Intel's latest and greatest for reference, as well.  Read on to see what we found out....

Specifications & Features: Socket 939 Athlon 64 FX-55 & 4000+
A Speed Bump & A New Name...
Maximum Performance
_The revolutionary architectural design of the AMD Athlon 64 processor maximizes performance for both current and future applications, resulting in fast application loading, awesome overall performance, and excellent multimedia experience.

Enhanced Virus Protection (EVP)
_AMD Athlon 64 processors are the first and only 64-bit client processors designed with EVP capability.

_This feature is enabled by an appropriate operating system, such as Microsoft Windows XP Service Pack 2 (SP2).

_When properly enabled, EVP is designed to significantly reduce the cost; damage; and infection rate of certain viruses, Trojan horses, and worms such as Code Red, MSBlaster, and Slammer.

Investment Protection
_AMD64-based clients provide leading software performance now, while allowing migration to 64-bit computing at the end user's pace.

Quieter Operation
_AMD technology enables dynamic performance on demand to conserve power and minimize noise.

_AMD Cool'n'Quiet technology for desktops reduces PC heat output and fan noise for a quiet work environment.

AMD64 - When utilizing the AMD64 Instruction Set Architecture, 64-bit mode is designed to offer:

_Support for 64-bit operating systems to provide full, transparent, and simultaneous 32-bit and 64-bit platform application multitasking.

_A physical address space that can support systems with up to one terabyte of installed RAM, shattering the 4GB RAM barrier present on all current x86 implementations.

_Sixteen 64-bit general-purpose integer registers that quadruple the general-purpose register space available to applications and device drivers.

_Sixteen 128-bit XMM registers for enhanced multimedia performance to double the register space of any current SSE/SSE2 implementation.

Integrated DDR memory controller:
_Allows for a reduction in memory latency, thereby increasing overall system performance.

An advanced HyperTransport link:
_This feature dramatically improves the I/O bandwidth, enabling much faster access to peripherals such as hard drives, USB 2.0, and Gigabit Ethernet cards.

_HyperTransport technology enables higher performance due to a reduced I/O interface throttle.

Fab location:
_AMD's Fab 30 wafer fabrication facility in Dresden, Germany
Large level one (L1) and level 2 (L2) on-die cache:
_With 128KB of L1 cache and 1MB of L2 cache, the AMD Athlon 64 processor is able to excel at performing matrix calculations on arrays.

_Programs that use intensive large matrix calculations will benefit from fitting the entire matrix in the L2 cache.

64-bit processing:
_A 64-bit address and data set enables the processor to process in the terabyte space.

_Many applications improve performance due to the removal of the 32-bit limitations.

Processor core clock-for-clock improvements:
_Including larger TLB (Translation Look-Aside Buffers) with reduced latencies and improved branch prediction through four times the number of bimodal counters in the global history counter, as compared to seventh-generation processors.

_These features drive improvements to the IPC by delivering a more efficient pipeline for CPU-intensive applications.

_CPU-intensive games benefit from these core improvements.

_Introduction of the SSE2 instruction set, which along with support of 3DNow! Professional, (SSE and 3DNow! Enhanced) completes support for all industry standards.

_32-bit instruction set extensions.

Process Technology:
_.13 micron SOI (silicon-on-insulator) technology

Die Size:
_Newcastle Core - 144mm2
_Clawhammer / Sledgehammer - 193mm2

Transistor count:
_Newcastle Core - Approximately 68.5 million
_Clawhammer / Sledgehammer - 105.9 million

Nominal Voltage:

Athlon 64 FX
Athlon 64

The chart above outlines the main features and technical specifications of the Athlon 64 FX-55, the Athlon 64 4000+, and the last two processors AMD released, the FX-53 and 3800+.  As you can see, the Athlon 64 4000+ and FX-53 processor share the exact same specifications.  They are essentially the exact same processor.  The 3800+ has half of the cache of them both, and as such it has a much smaller die size and a lower transistor count.  The Athlon 64 FX-55 is somewhat of a different animal, however.  Not only is it clocked 200MHz higher than the 4000+ or FX-53 at 2.6GHz, but its maximum ambient case temperature, maximum thermal power output, and maximum processor current draw are very different.  These changes stem from two factors: one is the FX-55's higher clock speed and two is the fact that AMD is now using strained silicon-on-insulator technology to manufacture the FX-55.

Using strained silicon modifies the electrical properties of transistors to increase their performance. Intel is also using strained silicon with newer versions of the Pentium 4.  There are varying ways of achieving transistor strain, but the end results are usually similar.  With strained silicon the atomic structure of the transistor's electrical path is strained into better alignment, which allows for improved electrical flow.  AMD has stated that it's still actively researching and developing the technique and that the method it used in the manufacture of the Athlon 64 FX-55 is only one manifestation of a series of strain technologies currently in development between AMD and its partners.  The company expects the process to be further improved and refined in the coming months and plans to disclose the details of this strain technology jointly with its partners in the future.

The FX-55 and 4000+ also share the same main features and benefits of previous Athlon 64 processors, namely Cool'n'Quiet dynamic clock speed technology,  Enhanced Virus Protection (EVP) when used in conjunction with the proper operating system, an integrated on-die memory controller, and the ability to run 64-bit code. (For a more comprehensive look at the underlying technology, see our initial look at the Athlon 64 here.)  A new version of Windows XP is already in its beta phase and can be downloaded right here.  We expect Microsoft to ship the final version of this OS sometime in the second half of next year.

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