Today is one of the biggest day's in AMD's corporate history as they are launching one of the most expensive processors they have ever designed. AMD will have retail processors available and expects system builders to be taking orders on systems today, September 23, 2003. Therefore the Athlon 64 and Athlon 64 FX should be on their way to their shelves right now. No paper launches on this one! Kudos to AMD for planning the launch date out far in advance on this one. Will their investment and ground breaking 64 bit processor for the everyday personal computer take off and keep Intel on their toes?

The Actual Processor:

The Athlon 64 FX-51 is built like an Opteron, which features the 0.13-micron manufacturing process with Silicon on Insulator (SOI). Since the Opteron has been around for awhile buyers can rest assured that AMD has the process perfected and therefore we should expect some pretty good processors initially. Since AMD has gone to the SOI technology they have been able to add additional frequency headroom and lower the operating temperatures of the processor. Higher frequencies and lower temperatures are something that will be appriciated by consumers. For those AMD Athlon XP users that have chipped or cracked their core you should be happy that AMD has gone with the integrated heatspreader on the all of the Athlon 64 FX's! Users can now install and remove their heatsinks with a lowered risk of damaging the core. The Athlon 64 FX-51 is rated at 2.2GHz and this is shown below by CPU-Z 1.19b.

General Specs

So what has changed as for as processor features? The graph below best displays the differences between the new Athlon 64 series of processors to the current Athlon XP processors.


AMD Athlon™ 64 FX

AMD Athlon™ 64

AMD Athlon™ XP

Architecture Introduction:




Process Technology:

0.13 Micron, SOI

0.13 Micron, SOI

Socket A


105.9 Million

105.9 Million

54.3 Million

System Bus:



Front Side Bus

Integrated DDR Memory Controller:

Yes, 128-bit + 16-bit ECC

Yes, 64-bit + 8-bit ECC


Total Processor-to-System Bandwidth:

12.8 GB/s

9.6 GB/s

3.2 GB/s

Total Processor-to-System Bandwidth:

12.8 GB/s

9.6 GB/s

3.2 GB/s

On-chip Cache:

L1: 128KB L2: 1024KB

L1: 128KB L2: 1024KB

L1: 128KB L2: 512KB

3-D and Multimedia Instructions:

3DNow!™ Professional, SSE2

3DNow!™ Professional, SSE2

3DNow!™ Professional

The New Die:

The current Athlon 64 FX has a die size of 193mm built using the 130nm (.13-micron) process. When AMD moves to 90nm (.09-micron) technology next year, the corresponding die shrink will bring die size on a comparable chip down to an estimated 120mm. This reduction in die size will also help bring down manufacturing costs.

HyperTransport Technology:

Since the current available bandwidth, between Northbridge and Southbridge chipsets have been noted as causing a data bottleneck that hurts computer performance, top computer designers have been looking for something to replace it with. The answer they came up with is, HyperTransport. HyperTransport technology is simply a high-performance, point-to-point link for integrated circuits. On the Athlon 64 FX-51 it will be able to transfer data at a bandwidth of 6.4GB/second! On paper this means that it can be up to 24 times faster than the current PCI bus.

HyperTransport is more of a protocol than a set physical interface, and it can be updated as needed for new applications which is a very nice feature to have. In the HyperTransport protocol, data are segmented into data blocks or packets. Each data block can be up to 64 bytes long. If everything keeps going like it is now and the end user accepts it as a standard, HyperTransport could eventually replace the PCI (Peripheral Component Interconnect), which has become a "legacy technology" for present day motherboards.

The old term front-side bus has always represented the speed at which the processor moves memory traffic and other data traffic to and from the chipset. Since the Athlon 64 has the memory controller located on the processor die, that memory subsystem traffic no longer has to go through the chipset for CPU-to-memory transfer. Therefore, the old term "front-side bus" does no good as it is not applicable any more. With AMD 64 processors, the speed a which the CPU and memory controller interface is Full Processor Frequency (FPF). The speed at which the processor and chipset communicate is dependent on the chipset's HyperTransport spec. Currently the AMD Athlon 64 FX and Athlon 64 can communicate to chipsets at speeds of up to 1600MHz.

Pin Counts:

On the flip side of things you can see how the 940 pins on the AMD 64 FX-51 (Middle) dominate over the Intel Pentium 4 3.0C's 478 pins (Left Side) and the AMD Athlon XP 1700+ DLT3C's 462 pins (Right Side). As you can tell by the above image the packaging costs will be higher than the Athlon XP due to SOI, one HT link and the 128-bit wide memory interface that is now present. Note that the Athlon 64 FX has only one HyperTransport link while the exisiting Operton has a total of three.

Now that you know the AMD Athlon 64 FX has the 940-pin count, what will happen once 939-pin non-registered memory processors comes out? AMD has confirmed that they will continue to produce AMD Athlon 64 FX processors in the 940-pin package throughout 2004. The 939-pin package (which should be out around the time of the PCI Express) will not be able to plug into 940-pin boards. But remember, the AMD Athlon 64 FX processor will be available in both 939 and 940 packages in 2004, meaning support should be around for at least the next 14 months for AMD's current flagship processor. Since this processor is designed for enthusiasts this should not be a huge deal as they are a group of people that tend update processors at least one time per year. But, we feel that it is something that should be addressed to our readers.


There is no doubt that the customer base for this processor will be the enthusiast community, and cooling is a big concern with the enthusiast community. Therefore, we decided to show you the temperatures we observed based on idle and full load situations with the processor. To record the temperatures, we had to use the Asus PC Probe (version V2.21.05) hardware monitor utility that we downloaded from the ASUS website for our ASUS SK8N motherboard. For the idle temps, we let the system sit on the desktop for 30 minutes. For the load temps, we ran Prime95 and loops of 3dmark to stress the processor until the processor tempraturess maxed out. Here are our results with the retail HSF and the Thermaltake Venus 12:

Default Settings

2.2GHz w/Retail HSF

2.2GHz w/Venus 12


37 Degrees C

31 Degrees C


51 Degrees C

42 Degrees C

Case Temp :

33 Degrees C

31 Degrees C

As you can tell the Athlon 64 FX-51 with the Silicon on Insulator (SOI) technology is able to pull off some very low temperatures! Although once we put on the just released Thermaltake Venus 12 HSF we were able to drop the idle temperatures down to 31 Degrees Celcius at idle! We also noted that the strong 80mm fan on the Thermaltake HSF helped cool the motherboard and memory as it moved the air around in the case more. Look for a full review on the Thermaltake Venus 12 when we have more time to use it.

Registered Memory & ECC Memory Info:

The AMD Athlon 64 FX processor does require registered memory in its current 940-pin configuration. The AMD Athlon 64 FX processor was designed to utilize Registered DDR up to and including DDR 400. The memory does not have to be ECC memory, but it can be if you want to run ECC memory. Will this increase costs? Sure, but remember that companies like Corsair are going to be coming out with DDR 400 memory that is Registered, but not ECC. As one would expect there will be a slight price increase from unbuffered to registered memory. Just today Kingston has released their Registered/ECC DDR 400 memory for the Athlon FX systems. At the time that this review was written the Kingston HyperX Registered DDR400 Modules were the only AMD vadilated micro BGA modules on the market. It seems that many of the other companies went with TSOP modules. Sounds like AMD and Kingston planned ahead on this one, so we have high hopes for it. Let's use the 1GB DDR 400 Kingston HyperX dual channel kits as a price example for Registered/ECC memory versus unbuffered memory.

Model #












Unless you have registered memory laying around it looks like many will have to go out and purchase new memory for their systems if they want to run the 64-FX. Below are two examples of PC-3200 memory that is Registered with ECC.

The top image is a module made by Legacy and the bottom is the Kingston HyperX module. We will be bringing you a full indepth review of the Kingston HyperX Registered DDR400 Modules in the near future after we do the torture test on them.

Test System

Our Intel Test System:

Driver Versions:

Our AMD Test System:

Driver Versions:

Testing Procedure :

All testing was done on a fresh install of Windows XP Professional build 2600 with Service Pack 1A and DirectX 9.0b. All benchmarks were completed on the desktop with no other software programs running. No overclocking was done on the video card durning any of this review. Our testing was done at 200x16 = 3.2GHz with H/T enabled on the Intel Processor and 200x11 = 2.2GHz on the AMD Processor. Please view the overclocking section for the overclocking details on the Athlon 64 FX-51 processor. We did disable the audio, USB, Firewire, and lan features if found in the BIOS menu for all the testing completed during this review.

Now for the results!


FutureMark; 3dmark2001 SE, Build 330:

FutureMark; 3dmark2003, Build 330:

Massive Development; AquaMark3:

The AquaMark3 executes a complete state-of-the-art game engine and generates 3D scenes designed to make the same demands on hardware as a modern game. The utilized game engine, the krass™ Engine, has been used in Aquanox and AquaNox 2: Revelation as well as in the upcoming RTS Spellforce by Phenomic Game Development. AquaMark3 utilizes recent hardware features of the new DirectX 9 API, such as PixelShader 2.0, while staying fully backward compatible to DirectX 8 and 7 graphics hardware

CodeCult; Code Creatures Pro:

The Codecreatures benchmark is written with Microsoft's DirectX 8.1 API and incorporates the use of Vertex and Pixel Shaders popular on next generation 3D accelerators. The benchmark plays a photo-realistic nature scene and calculates the performance of the graphics adapter and processor by measuring the FPS that it can display at 1024x768, 1280x1024 and 1600x1200 resolutions.

Standard Performance Evaluation Corporation; SPECviewperf 7.1:

SPECviewperf 7.1 is a professional OpenGL rendering benchmark that can evaluate the performance of OpenGL rendering in a professional workstation environment.

More Benchmarks

Futuremark; PCMark2002:

PCMark is another benchmark from MadOnion which is a whole system benchmark. PCMark specifically stresses the CPU, memory subsystem, graphics subsystem, hard drives, WindowsXP GUI (if WinXP is used), video performance and more.

Sisoft; Sandra MAX3:

Sisoft Sandra MAX3 is designed to test the theoretical power of a complete system and individual components. The numbers taken though are, again, purely theoretical and may not represent real world performance. Higher numbers represent better performance.

FutureMark; Bapco SYSmark2002:

SYSmark2002 provides an application-based benchmark that accurately reflects usage patterns for business users in the areas of Internet Content Creation and Office Productivity.

Science Mark 2.0:

Science Mark 2.0 is an attempt to put the truth behind benchmarking. In an attempt to model real world demands and performance, ScienceMark 2.0 is a suite of high-performance benchmarks that realistically stress system performance without architectural bias. For the Memory Testing, higher numbers represent better performance. On the remaining tests, lower seconds represent better performance.


CINEBENCH 2003 is the free benchmarking tool for Windows and Mac OS based on the powerful 3D software CINEMA 4D R8. The tool is set to deliver accurate benchmarks by testing not only a computer's raw processing speed but also all other areas that affect system performance such as OpenGL, multithreading, multiprocessors and Intel's new HT Technology. Again, higher Frames/Second and lower rendering time in seconds equal better performance.

SuperPi 1.1e:

SuperPI calculates the number Pi in this raw number crunching benchmark. The benchmark is fairly diverse and allows the user to change the number of digits of PI that can be calculated. In this benchmark we picked 2 and 4 million places.

Case Lab CFD Solver:

The benchmark testcase is the AGARD 445.6 aeroelastic test wing. The wing uses a NACA 65A004 airfoil section and has a panel aspect ratio of 1.65, taper ratio of 0.66, and a quarter-chord sweep angle of 45º. This AGARD wing was tested at the NASA Langley Research Center in the 16-foot Transonic Dynamics Tunnel and is a standard aeroelastic test case used for validation of unsteady, compressible CFD codes. The CFD grid used to model this problem consists of 67,435 nodes and 366,407 tetrahedral elements.

Thoughts: A huge drop in time was observed in Case Lab, Super Pi, Science Mark 2003, and SuperPi. This processor cut 39 seconds off the P4 3.2C's best score in Case Lab CFD Solver benchmark! Although we can not figure out why when overclocked it ran slower in Case Lab CFD. We tried it many times with similar results so we kept the data. On SuperPi we saw the Athlon 64 FX-51 finish almost 30 seconds faster than the P4 3.2C processor! Now that really does show some processing power! We are not talking a few seconds here! So far AMD is looking impressive!

Even More Benchmarks

NovaLogic; Comanche 4:

The Comanche 4 benchmark demo is a unique benchmark as it represents a real-world gaming experience. It contains the single player Eagle's Talon mission from the game as well as a detailed cinematic. This DirectX 8.1 benchmark demo measures your system's performance in the standard frames per second format.

Epic Games; Unreal Tournament 2003:

Using the the full installation of Unreal Tournament 2003 along with the newest patch gives us a very nice real world benchmark! We also used [H]ardOCP's UT2003 Benchmarking utility version 2.1. Resolutions of 1024x768, 1280x1024, and 1600x1200 were tested in Direct3D on the built-in CPU test.

Activision, Inc; Return To Castle Wolfenstein w/ version 1.4 update:

Return to Castle Wolfenstein is a game based on a modified Quake3 engine. It uses pretty much the same console commands and is just as easy and reliable to use benchmark with as Quake3 Arena was. Since this is a newer game we feel that the results mean more than what we find in Quake3.

Thoughts: We have included percent difference charts in this section as we feel these are some of the more looked at charts in this review. It is clear that the AMD Athlon 64 FX-51 dominates the video game benchmarks that we ran here. I think the most amazing is how the Athlon 64 FX-51 is 23% faster than the Intel P4 3.2C processor on UT2003 at 1024x768. That is a 34 frame per second increase on average! It is important to note that the 1600x1200 results on UT2003 show that we are video card limited! Return To Castle Wolfenstein uses a modified Quake3 graphics engine and we found around a 13% increase on performance, which again is often a 30 FPS increase there also. We ran our benchmarks at 1024 x 768 and up to help show how the real world will benefit from these processors. Running a benchmark at 640 x 480, but running the games you play at 1024 x 768 or higher does not make sense.


As always we must overclock and push new technology to the edge and find the breaking points. Lately Legit Reviews has been going for stability and quality of our overclocks rather than showing a single benchmark and showing off unstable results. When it came to overclocking the AMD Athlon 64 FX-51 we first tried to find the maximum overclock with the default voltages and had some pretty good success. Our final stable overclock at default voltage was 2.31GHz and this is what we ran in all the benchmarks while overclocked in the benchmark graphs.

As for how much futher the Athlon 64 FX-51 can go, I guess you will have to wait as just in the past 4 days we have gotten in Kingston HyperX Registered/ECC PC-3200 and the Thermaltake Venus 12 cooling solution that may aid in overclocking beyond where we are at today.


Nathan Kirsch's Thoughts:

I must say after having the Athlon 64 FX-51 up and running every day now for over a month that the Athlon 64 FX-51 is definantly ready to be used by the enthusiasts. It is nice to have a low temperature AMD Athlon processor in the computer that is able to top the current Intel processors that one can buy today. We know the Pentium 4 EE has been announced, but none are on the shelves yet and even we do not have one yet as only few are available. Consumers need AMD and Intel to stay in close competition as both companies will turn out products quicker and more often at a lower price to win market shares. A big kudos goes out to AMD for bringing 64 bit technology to the high-end home user market before 2003 comes to an end!

With the initial MSRP of US $733 on 9/23/2003 the Athlon 64 FX-51 is not in the price range for everyone, but it is right on target for the the enthusiast that wants the ultimate level of performance that also wants to be able to use 64 bit applications as they start hitting the market here in the near future. It is going to be the 64 bit applications that will be the biggest hurdle for the Athlon 64 processor to become a hit. As far as rendering time and gaming performance is concerned the Athlon 64 FX-51 is in a league of it's own, but it really needs 64 bit software on store shevles before end users can justify the price. We have also had a chance to take a look at Windows 64 Beta and I must say it is pretty darn stable for being in Beta form still. Once Windows 64 releases I believe many more users will purchase the 64 bit processors since the added speed of Windows 64 is really impressive and will be much welcomed by power users.

I see a pretty bright future for the Athlon 64 FX series of processors as AMD has left some room to make improvements to the processor. The first thing that comes to mind is the ceramic packaging found on the Athlon 64 FX processor. The move to organic packaging will allow for future increases in speed when the time arises. From the initial processor release it seems as if AMD has done their homework and if software developers support AMD and come out with 64 bit applications quickly the Athlon 64 FX will be the processor to have! 64 bit applications are coming and this is the dawn of new hights for all computer users. The main company we have to thank for this is AMD and the people who do all the work to make this possible. Someone had to be the first to lay the foundation for 64 bit processing and AMD stepped up to the challenge with good results so far!

Will AMD's investment and ground breaking 64 bit processor for the everyday personal computer take off and keep Intel on their toes? Only time will tell, but they have the technology and resources in place to do it!

Keep an eye on our site as in the near future we will have reviews on registered memory, Athlon 64 FX cooling solutions and the conclusion to our Athlon 64 FX-51 overclocking section.

Justin West's Thoughts:

After performing many tests on our Athlon 64 FX-51, I feel that AMD has definitely done their homework on this chip. Those who have the cash to purchase a 64 FX-51 will definitely be happy with their chips performance. Now the big question: What kind of person will actually buy this processor?

This processor has quite a few strong points that could show light on AMD’s 64-bit processor line: it runs cool, can utilize ECC Registered Memory, 64-bit technology, and is currently only 2.2 GHz. I think that the last point mentioned is where AMD has the most potential. You have seen our results against a 3.2C Pentium 4, so what kind of performance increase would we get if you ran a 64 FX-51 (or the 939-pin version) at 2.6 or 3.0 GHz? Hopefully that day will come soon!

The place where I see the Athlon 64 FX-51 doing best right after launch is in businesses. I see these processors being used as a workstation or small file server in a setting that would utilize the ECC Registered Memory feature. It is in this setting that I also see users compiling a 64-bit version of Linux as the operating system.

With that said, I have not forgotten that the Athlon 64 FX-51 performed its best in gaming benchmarks. However, I do not see the need for a 64-bit architecture and ECC Registered Memory for a gaming system, YET! If gamers want to reap the gaming benefits from the Athlon 64, I expect the majority of them to wait just a little longer for the 939-pin version. This way they do not needlessly have Registered Memory.

The last point I have to make is the price. We all know now that Intel has released their P4 EE (Extreme Edition) with extra on-die cache which may challenge (or surpass) the Athlon 64-FX’s performance. However, with both of these processor’s being over $700 on price, I do not expect many customers to buy one this second. If a customer wants to get a better price:performance ratio, they will stick with a processor like the P4 3.0C. Especially since the release of the P4 EE, Athlon 64, and very soon, Intel’s Prescott, will only lower the price of the P4 “C” processor line.

As for an ending note, AMD has been playing catch-up with Intel in the processor market. Now it seems as if AMD has finally caught up and will now be on an even playing field hopefully for some time to come. I would also not expect AMD R&D to just sit on 2.2 GHz. They will be frantically working to keep their place neck-to-neck or higher against their rival. I only expect good things in the future processor market because of AMD’s hard work!