Thunderbird-Slot A

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We’ve decided to try something different here. After talking with the folks from Overclockers Austria, we decided to take one of their articles, adapt and update it and publish it here. In turn, some of our articles will be adapted for their site. Tell us how you like this idea.


Beginning with the K6, AMD has been able to at least hold its own against Intel.

Still, the real breakthrough only came with the introduction of the Athlon a year ago; providing high quality along with low cost. Though the Athlon only offered an off-die L2 cache while the Coppermine switched to on-die cache, it generally matched and often beat its Intel competition.

Overclockability was another strong point for the Athlon. Unlike the PIII, the Athlon’s multiplier
was not locked. A “Golden Fingers” card could easily adjust the multiplier and voltage of the CPU.
Many Athlons proved very overclockable, providing even more performance for less money.

“Thunderbird” is the newest generation of Athlons. The Thunderbird sports an on-die 256Kb L2 cache to go along with the Athlon standard 128Kb L1 cache. The CPU is made using the 0.18 micron process, using over 37 million transistors. While earlier Athlons had 512Kb of L2 cache, the increased speed of ondie cache more than makes up for its reduced size.

Additionally, with the Thunderbird, L1 and L2 cache can now work separately, unlike earlier Athlons.

The Thunderbird is currently available at speeds from 650Mhz to 1Ghz. There will be two versions: slot A and socket A.


Before the official release, there were rumors to the effect that the Slot A version of the Thunderbird wouldn’t work with KX133 motherboards. We had no problems running the Thunderbird on the most common boards from ABIT and ASUS. We always use the newest version of the BIOS when installing a new CPU, something you should do, too.

Newer AMD750 Motherboards had no problems at all with the Slot A versions. There is even a Socket 1 -› Slot 1 adapter announced for the near future by at least one German company. The company says there is a “high probability” a card will work with AMD 750 chipsets; they aren’t so sure about the KX133. See here for the announcement, and here for translations.

Socket A (Socket-462):

When will we see Socket A T-Bird systems? When the KT133 chips don’t make problems anymore.:) At the moment there are incompatibilites with some SDRam modules and the AGP4x mode.

The KT133 is essentially the same as the KX133 chip. The only differences are that the KT is designed to be a socket A motherboard with the optimal timings to work with the Thunderbird.

Why a Slot A version? AMD had a few reasons. Since the KT chipset had a few problems, some platform needed to be available at introduction.

Slot A Thunderbirds are only a transitional chip. Socket A is the future for the Thunderbird chip because socketed chips are a lot cheaper to make, as Intel is demonstrating.

Benchmark Setup:

System 1

  • Processors: “Thunderbird” 700 | Athlon 900 | Athlon 500
  • Motherboards: ABIT KA-7 | ASUS K7M
  • Memory: 256 SD RAM 100 MHz 6ns
  • HDD: IBM-DJNA-351520 UDMA-66
  • Video: Hercules Prophet II 32 MB
  • Cooler: Global Win VOS32

    System 2

    • Processor: Intel Pentium III (Katmai) 600B (133MHz FSB)
    • Motherboard: ASUS P3B-F 1005 Bios
    • Memory: OEM 384 MB SDRam 133MHz 6ns
    • HDD: 2x IBM-DPTA-372050 an Promise Fasttrak66 (Raid0)
    • Video: Hercules Prophet II 32 MB

    Driver Setup/OS:

    • Detonator 5.22
    • VIA AGP 4.03
    • DirectX 7.0a
    • MS Windows 98 SE


    • Quake III Arena 1.17n
    • 3D Mark 2000
    • SPEC viewperf 6.1.1
    • Sandra 2000 Pro

    Quake III Arena 1.17n:

    As you can see, the Thunderbird revs up well at higher speeds. The higher the speed, the better the Thunderbird will look against its ancestor Athlon. Its L2 cache is running at full speed, which the older Athlon at high speeds has an L2 ration of 2/5 or even 1/3. Overclocked at 840Mhz, the CPU was as fast as the Athlon 900.

    At lower resolutions (640×480 and 800×600), the P3-600B is a bit faster than the Thunderbird. Likely causes are the Geforce drivers, the AGP4x problem, and the increased FSB. With the faster CPUs (800+) you can see that the Geforce2 GTS is used to its maximum. Updated drivers optimized for the Thunderbird are likely to improve performance.

    3D Mark 2000:

    3D Mark 2000

    The T-Bird does fine here. In 16-bit mode, it does almost 200 3D Marks faster than the Athlon 900 at 840Mhz. 32-bit mode also shows better performance.

    SPEC viewperf 6.1.1:


    More of the same: 800MHz or more makes the T-Bird fly. Of course the 700MHz version isn’t slow 🙂

    SPEC viewperf 6.1.1 is a pure OpenGL Benchmark. Specbench offers more possibilities for high end graphics-testing.

    Sandra 2000 Pro:

    The T-Bird at 700Mhz . .

    . . . and at 840Mhz


    AMDs newest CPU again will be overclockable, by both FSB and with the aid of a “Golden Fingers” card (unfortunately only the FreeSpeed Pro Card worked with our tests). The multiplier and core voltage can be changed, though you can also manually set this in the BIOS of newer KX133 boards like ABIT KA-7 or ASUS K7V.

    I could overclock the CPU I received from Alber-EDV with 120 FSB on a ABIT KA7. With the OC card I could even go up to 975 MHz, but couldn’t even boot Windows. So I had to go along with 900, but that at that speed my system also crashed sometimes. Maybe I need more cooling. 🙂

    If a cooler works with an old Athlon; it should work with a Thunderbird.

    So, how do I know what the Thunderbird looks like? You can see that the housing of the CPU is black, the heatplate is silver – same as the Athlon 900 or higher.

    Overclocking a Socket A
    How you can overclock a Socket A? The Asus A7V will let you do it by changing multiplier on the motherboard. The upcoming QDI board is supposed to do the same thing. Don’t assume all Socket A boards will be able to do this; the others that are available or will be released shortly cannot. You definitely want to wait until one of these two boards become available.


    Looking at the prices right now, you should probably get a Thunderbird 700 Slot A – if available. At a price of about $180US, the T-Bird is not much more expensive than a 700Mhz Athlon, and will perform better when overclocked.

    You should be safe running these T-Birds with motherboards that use the AMD 750. Don’t be so sure about KX133 motherboards. though. At the moment only ASUS and ABIT can and should be used.

    The T-Bird 700 is AMDs first offering. Within weeks, Duron, Socket A Thunderbirds and KT motherboards should be available. In 3-6 months, the high-end CPU “Mustang” along with DDR and SMP motherboard will become available.

    Email Teischl

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