Sigh, the Athlon 64 FX

With the release of the 865PE and 865G chipsets, Intel has ensured that virtually all Pentium 4 processors on the market are paired with very high-bandwidth dual-channel memory subsystems. Ignoring the performance boost Intel gains by going to dual-channel, OEMs demanded a dual-channel solution from AMD simply as a checkbox feature.

Not having the time or resources to undertake introducing a brand new dual-channel desktop processor, AMD simply took their existing dual-channel design and called it an Athlon 64 FX. The existing design was the Opteron of course, and the first incarnation of the Athlon 64 FX is almost directly borrowed from the Opteron. What do we mean by directly borrowed?

For starters, the Athlon 64 FX gets the Opteron's memory controller with a slight change - support for DDR400. Offering DDR400 support on the server side is a little trickier than on the desktop for a couple of reasons; server processors must go through more validation than their desktop counterparts and adding DDR400 to the list of validated configurations would increase testing time. Then there's the issue of bringing DDR400 support to motherboards; an issue whose complexity increases tremendously as the number of memory slots you have to support grows. Given the memory requirements of the server market (and associated memory slots), it's just easier to wait on DDR400 support.

On the desktop, DDR400 support is great and the 128-bit memory controller from the Opteron is also nice to have, however there is one issue with the Opteron's memory controller that made its way to the desktop - the memory controller only supports buffered (aka registered) DIMMs. Although AMD is launching with Kingston releasing a line of HyperX registered DDR400 DIMMs, the vast majority of the desktop users have invested in unbuffered DDR400 DIMMs and spending more on registered DIMMs isn't exactly an easy pill to swallow.

AMD's justification for no unbuffered support is that the Athlon 64 FX is for the "enthusiast" community and these "enthusiasts" will want to use lots of memory of densities that are currently only available in registered module sizes. Given that very few "enthusiasts" have registered DDR400 it seems much more likely that it was simply easier to re-badge the Opteron than modify the CPU to support unbuffered memory.

What is necessary to add unbuffered support? Unfortunately, it is a CPU packaging issue and not something that can be added on the motherboard (remember, the memory controller is on-die now). AMD plans on adding unbuffered support to the Athlon 64 FX, but that will come at a later date as they will have to redo the chip's packaging. It seems likely that AMD would introduce unbuffered support with the rumored 939-pin Athlon 64 FX due out next year since they are changing the package anyways to support a different pinout.

Although AMD says that the Athlon 64 FX is for use in single processor environments only, the current version appears to have all three Hyper Transport links - meaning that it can work in multiprocessor environments just like the Opteron. AMD has indicated that future versions of the Athlon 64 FX would only have a single Hyper Transport link, but there's no way of knowing when that will be.

With the Athlon 64 FX, AMD has abandoned their model number system in favor of a series nomenclature similar to the Opteron. For example, the first Athlon 64 FX is the series 51 CPU, running at 2.2GHz. The number 51 was chosen arbitrarily (AMD confirmed this) and indicates nothing about its performance relative to any chip other than the Athlon 64 FX. The next CPU due out next year will be the Athlon 64 FX 53, and all you are expected to know is that 53 is faster than 51.

There's no criticizing AMD for their Athlon 64 FX series numbers simply because it was our distaste with their original model numbers that brought this nomenclature about. We criticized the Athlon XP for using model numbers in the first place, we complained when AMD rated their processors to conservatively and then we lashed out at them for being too aggressive with the model numbers. Look at the facts, AMD labels the Athlon 64 FX as an "enthusiast" processor, only sends Athlon 64 FX parts out to reviewers - the fact of the matter is that AMD doesn't want to face criticism about their naming system any longer so they've removed it where possible, and kept it where they thought it was necessary. AMD will get no complaints from us about the series numbers attached to the Athlon 64 FX, it remains to be seen if the Athlon 64's model numbers will suffer the same fate as the Athlon XP's.

The FX goes back to using a ceramic package, as opposed to the organic packaging that the Athlon 64 uses. Both processors have an identical 193mm^2 die size (which is massive, these will be expensive chips to make) and are made up of 105.9 million transistors. The chips run at a 1.50V core voltage.

The 940-pin Athlon 64 FX will work in all 940-pin motherboards and the Athlon 64 FX 51 will be priced at $733 in 1,000 unit quantities.

AMD's Gem: Athlon 64 Socket-939: Athlon 64 FX DOA?
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  • Anonymous User - Wednesday, September 24, 2003 - link

    Nice review anand, however I am missing the P4 EE in a number of the tests, as previous post (#67) suggested.

    The Athlon 64/A64 FX appears to be a nice processor, for a shiny new design cpu the advantages were expectable.

    Some more 64bit tests, maybe a divx codec pre-compiled for 64bit in a test?

    As for the amd vs intel combat:
    The A64 and A64FX match up a lot better against the latest p4/p4EE. I wouldnt have expected anything else.
    While the prescot still lurks in the dark and I have a feeling Intel has something up their sleeve I wouldnt call the prescot an failure yet.
    If Intel plays nicely along, maybe they can create a cpu that beats the A64/A64FX in 32 (and just maybe in 64bit http://www.theinquirer.net/?article=11668).

    Either way, the more AMD and Intel compete each other, the happier I am, after all I end up paying less for either cpu.
  • Anonymous User - Wednesday, September 24, 2003 - link

    There is already a 64 bit port of America's Army available that doesn't need a 64 bit OS! http://www.amd.com/us-en/Corporate/VirtualPressRoo...
  • Anonymous User - Wednesday, September 24, 2003 - link

    Guys, if the AMD Athlon 64s don't succeed, I believe AMD would go under or be in financial trouble. So these new processors MUST sell well.
  • Anonymous User - Wednesday, September 24, 2003 - link

    I'm curious why RedHat Taroon, which is an enterprise-focused Linux distribution, was used for the 64-bit benchmarks and not RedHat GinGin64, which is more consumer-focused. Both are available from the RedHat FTP site.
  • Anonymous User - Wednesday, September 24, 2003 - link

    Several of the benchmarks left out the P4 Extreme scores (memory bandwidth, Content Creation 2003, and Virtual Studio 6.0 Compile) - was that a mistake or benchmarking per AMD's new guidelines? It's also funny that this is one of the first Anandtech CPU reviews without the full system specs documented (i.e. ECC memory vs non ECC, Intel branded motherboard vs. ASUS enthusiast motherboard, memory latency settings, etc.) - more AMD review guidelines?

    The way I see it, you can either spend the money on a whole new Athlon 64/FX CPU, motherboard, and memory outfit, or buy a P4 EE and stick it into any motherboard today that accepts a 3.2 GHz CPU - that sure beats having to buy a new motherboard and memory to get about the same level of performance average across the board.

    Even when 64-bit Windows comes out, does everyone really think that Microsoft and Bill Gates will really make it priced at mainstream levels and reduce the cost of the current 32-bit Windows XP so soon? I have my doubts but I guess we'll just have to wait and see.

    Another interesting thing to note from Tom's Hardware review is that the 64-bit code for AMD64 does run faster on 64-bit OS but if you read carefully, he says that the same program optimized for the P4 runs even faster on 32-bit OS. So, software companies will probably have to make a choice (unless they are big enough and make enough money to serve all markets): A - optimize 32-bit software to take advantage of the P4/Prescott and Hyperthreading using compilers that Intel provides, or B - compile 64-bit software for which there is still no mainstream OS and there are hardly any standard compilers available for and market them to the 500,000 or so people who will have the opportunity to own AMD64 desktop chips this year.

    Sure Intel has a problem with the Prescott heat dissipation right now but I don't think they will be sitting idle. Thermal interface technology is getting better all of the time and I wouldn't doubt if Intel isn't already making process improvements and/or implementing newer cooling methods. After all, it was Intel who came up with the heatspreader design for the current generation P4 that is now being used by Hammer chips.

    Once the Prescott on .09-micron technology hits the streets it will continue to be refined and improved upon so the clock speed will continue to increase. Imagine a Prescott EE CPU with 1MB L2 and 2MB L3 or more. What would be a real thorn in AMD's side would be if Intel makes a shrink of the current P4 onto the new .09-micron technology and increases the clock speed to the 4 GHz level (already achievable by some CPUs on the current .13-micron process) to keep pace with the Athlon 64/FX which is supposed to be AMD's next generation CPU. They could put a whole bunch of P4 die (even P4 EE die) on a 300 mm wafer and put a hurting on AMD until they can get their 90nm process and 300mm wafer process going. It is a scary possibility for AMD but could be reality for Intel - meanwhile, AMD still has to face the daunting task of converting to 300mm wafers and 90nm process at the same time to keep up. AMD says that they will start 90nm production in the first half of 2004, but then again, they've been promising hammer since 2001. But they have to do something because with their current situation of roughly 192 square millimeters per Athlon 64/FX die on a 200mm wafer yields a theoretical 73 die per wafer (per Tom's Hardware review). And I believe that AMD wants to put all of their products on the same line and differentiate them at the end - similar to the way Intel does with their Northwood/Celeron products (same die with certain cache and other things disabled) - so even the 256K L2 cache mainstream Athlon 64 comes out, it may still be the same size as all of the other Athlon 64/FX/Opterons.

    Hector Ruiz, Jerry Sanders and AMD as a whole have a very steep mountain in front of them to climb. Time will tell if they have what it takes to get up and over it. The first checkpoint for them will come in about 3 weeks in the form of Q3 earnings. By then we'll see how sales of their new CPUs are going and if their joint venture in FLASH pays off. (It didn't really make sense to me for them to lay off 2000 people at the beginning of the year to reduce costs and then turn around 2 quarters later and pick up 7000 people in the FLASH venture with Fujitsu which comes with more debt than earnings.) I'm not a betting man, but if I were, my money would be on AMD making 9 straight quarters of losses in a row. When Hector Ruiz came to office he vowed that AMD restructuring would make them hit break-even sometime around Q2 2003 but that never happened. There seems to be a pattern with promises made by AMD. I guess it's why his 3 million stock options which were granted at $16 are still under water.
  • Anonymous User - Wednesday, September 24, 2003 - link

    Apparently the FX series is unlocked multiplier, and mobos will be coming shortly that have multiplier selection options (read Anand's "weblog" entry)... I can't wait to see the results of a 13x 220 FX-51; now, THAT I might part with $800 to play with... Talk about insanely fast processors, the higher FX goes, the smaller Intel's lead gets.
    Whoever said that throwing more cache on the P4 core beat Hammer is just deluded; P4 is at the end of its line, AMD64 is just beginning. And once again, Intel supporters seem to grow rather silent when you point out that the on-die memory controller becomes significantly more powerful when the clock speeds ramp up; a 3.3GHz FX chip would be more than a match for a 3.4GHz Prescott, I'd think. Memory bandwidth advantage is a thing of the past for Intel, now it's up to AMD to shore up their lacking SSE/SSE2 performance and work on speeding up the core, as well as meeting the demand for such upgraded processors.

    I'm not normally so pro-AMD (though I support their products more than Intel's, just from a cost efficiency standpoint), but it's kind of hard to not be wowed by the muscle this chip can flex. I mean, this is the Day One marketed "prototype" and it's capable of matching its most recent and mature rivals, can you imagine what next year is going to look like?
  • sprockkets - Wednesday, September 24, 2003 - link

    The fact that Intel HAD to release a EE edition shows desparation at looking behind. Yeah, so the Prescott does look good. That and the 103w dissipation, unconfirmed if it is on the 90 process, if it is then that's pathetic.

    I can buy a Athlon 64 or FX, where is the EE like others said? And why was the NDA lifted on the same day as the AMD Athlon 64?

    Complaining about price? The 1.5ghz P4 costed around $1000 when it came out and was slower than a P3 1.0ghz, while the new Athlon 64 always is faster than the XP.
  • Anonymous User - Wednesday, September 24, 2003 - link

    lmfao

    AMD is still the underdog :P Always will be. You get what you pay for.

    AMD is for the guys who love to root for the underdog; in otherwords fanboys. If you want solid, no hassle performance with top support .. you know where to put your money.

    I mean christ, Intel doesn't even have to design a next generation core to outmatch AMD's next core eveolution -K8- they just simply tack on more cache ;) How sad is that?

    AMD fans, take a hint ... AMD's STILL playing cat-up with Intel. Read the article closely, and you'll see what I mean -the author hints at it so clearly as well- Its so easy to see. AMD has never had the advantage ;) Only clever marketing which most people pin as bad marketing on AMD's part. Quite the contrary, Stupid kids!
  • Anonymous User - Tuesday, September 23, 2003 - link

    #61 ya I know how they compare...the g5 is a mac no software support and the cartoons might pop out of the screen and eat you.....no comparison....
  • Anonymous User - Tuesday, September 23, 2003 - link

    Which chip is faster at Divx encoding?

    http://www.anandtech.com/cpu/showdoc.html?i=1884&a...
    OR
    http://www.hardocp.com/article.html?art=NTI0LDM=
    OR
    http://www.aceshardware.com/read.jsp?id=60000256
    OR
    http://www4.tomshardware.com/cpu/20030923/athlon_6...

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