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This covers some of the most asked questions about AMD products. — Asmodean, n2 and SickBoy

1. How do I unlock my Athlon/Duron (covering both Slot and Socket A)?

For Slot A processors, you need to obtain a Gold Finger Device (GFD). This device
connects to some connectors inside the casing on your Athlon and give you the ability to
modify the multiplier via DIP switches or dials. They’re available from
overclocking shops on the web or on eBay and most will come with instructions.
Note: You will have to de-case your Athlon to connect it. See here for instructions.

For Socket A Athlons and Durons: (TBirds and Spitfire core Durons), a picture better be worth 1,000 words, as it takes longer to load.
Here’s what I find to be the best explanations:
Tom’s Hardware

2. Why can’t my KT133 motherboard run at 133Mhz FSB, or even close to it??

Via technically only supported 100mhz FSB on this chip, thus the KT133A was
released, having “official support” for 133MHZ FSB. Most DDR chipsets for
socket A also support a true 133 MHz FSB.

3. What are good heatsinks for socket A chips?

There are a number of good solutions, with new contenders entering the market
daily. Unfortunately, neither the one that comes as part of the retail AMD package, nor
most cheap heatsinks sold with them by retailers are very good. Expect to pay at minimum
$20 for one, and most good ones will cost between $30-40.

The basic rule is to find the C/W rating of the unit. Currently, the goal
is a number lower than .25 C/W. The Millennium Glaciator, the Swiftech MC462,
and the Thermalright SK6 are favorites at this time of writing.

Generally, the cheaper “good ones” will tend to use a high-speed, noisy fan; the Delta
7K being a favorite. That will sound like a small vacuum cleaner. The quieter ones
will use lower-speed fans, but tend to weigh (and cost) more.

4. What is the register 52 tweak and how do I do it?

The register 52 tweak enables the Halt-on-idle command on Via KX133, KT133,
and KT133A chipsets. Register 52 is a specific position in the KT/KX northbridge
and by changing what value it is programmed to, you enable halt-on-idle. What that does is essentially
throttle the CPU way back when it isn’t doing much.

Typically, users that enable the Halt-on-idle see a significant drop in idle
temperatures of 4 to 5 or more degrees celsius. It is done with WPCREDIT and
WPCRSET. You use WPCREDIT to temporarily change register values to see if the
tweak works for you, and if it does, you use WPCRSET to automatically apply
it every time you boot up Windows. You are not actually changing your BIOS – just
the mirror of the BIOS in your memory. As such, you need to do this for every
Windows installation you run, i.e. if you multi-boot 98, 2K, XP or any combo of
those, you need to do it for each OS. You also need to do it again after a
re-formatting and fresh installation of Windows.

Here is an URL
that describes the tweak in detail. The article includes all the links for the files you need and how to do it.

You must have ACPI enabled in the bios and in your OS for this to work.

This doesn’t always work properly. One user reported his NIC card (Netgear FA310TX) would not
transfer data of significant size (such as email with attachments) while Reg 52,
EB was in effect. Another user reported Winamp would lock up with this setting,
though Media Player worked.

5. What is a good motherboard for AMD processors?

Our (FAQ authors’) favorites (RAID Versions not denoted, usually they perform
identically when compared to a non-RAID version):

Socket A, PC133 SDRAM BASED:
Iwill KK266 and KK266 Plus
ECS K7VZA (not a good overclocker but stable and a good performer)
Abit KT7A, KT7A and KT7E
MSI K7T Turbo
Epox 8KTA3

Socket A, DDR BASED:
Epox 8KHA and 8K7A
Shuttle AK31 revision 2
Abit KG7
ECS K7S5A (not a good overclocker but performs very well at stock speeds)
MSI K7 Master
Asus A7V266

Socket 7 (K6-2, K6-3 and + Series chips):
FIC VA503+
Epox MVP3G2 and MVP3G5
Asus P5A and P5A-B
Tyan Trinity K6

6. What kind of power supply should I have for my AMD motherboard/processor?

See questions 10 and 11.

Otherwise, most of us Forum dwellers would recommend at MINIMUM, a 300W name
brand power supply unit for your Athlon, a 250W unit for a non-overclocked Duron.
A 250W unit is more than enough for any K6-2 or lower system.

Remember, overclocked AMD Athlons and Durons consume massive amounts of power,
which can be exacerbated given the extras you use and which video card you choose
(GeForce cards are notorious power suckers). Each fan, drive or other component
you connect to your PSU adds drain to your system, so select one with that in

7. What is the 686B bug, how do I know if I have it, and how do I fix it?

The 686B bug causes data corruption,and is most frequently assosciated with
the use of a SoundBlaster Live! card. A very detailed explanation and a list of
available fixes can be found at Via Hardware
(this affects Via 686B chipsets only).

Official statement from VIA:

“The data corruption error, which some web sites and people have reported with
the 686b Southbridge,is caused by incorrect bios registry setting to the
Northbridge. These bios settings were made by motherboard manufacturers, in an
attempt to fix a conflict with the Sound Blaster Live Value cards. Information
has been provided to all motherboard manufacturers on how to correctly resolve
both the data corruption error and the Sound Blaster Live conflict.
The patch released by VIA in the 4in1 4.31 drivers’ replicates the correct bios
settings. We provided this patch to make sure as many people got a fix to their
Sound Blaster Live problems as soon as possible. Most motherboard manufacturers
have now corrected their bios and the patch is not necessarily needed,
although it will not harm any VIA based system if installed.”

The Official fix is to install the latest 4-in-1 Drivers which you will find
on the VIA homepage.

The 4.32 drivers which also contain the fix appear to work better for a lot of
systems then the 4.31.

Another option if you do not wish to change your 4-in-1 drivers is to download
the beta fix released by VIA, which is located here.

It is not critical to upgrade your 4-in-1 drivers if you are happy with
the version you have. The 1.0 VIA patch will fix the problem for you whether you are
using the VIA IDE controller, or the Microsoft IDE Drivers.

Another source for a fix are upgraded BIOSs that many of the motherboard companies have now provided.
You should check to see if your mobo has one. An example of this is the ZT bios from ABIT for their
motherboards using the 686b Southbridge, this has been claimed to fix this
problem without installing the VIA fix.


N2 and


8. What is voltage modding and how can I do it?

This depends on your board, and usually consists of soldering a resistor onto the
mobo. However, you can mod your Athlon or Duron by connecting bridges. see here for

There are two kinds of voltage mods: CPU core voltage mod and I/O voltage mod.

The first allows you to give your CPU more core voltage, giving the possibility
of achieving higher speeds, with increased heat output. Normal air cooling is not
enough to handle the raised heat production.

The latter will let you give more voltage to the northbridge, allowing for higher
Front Side Bus speeds (FSB). This will also increased the heat output, resulting
in the need of active cooling for the northbridge, sometimes even the memories.

You can find guides for doing different voltage mods for various motherboards at

9. Can I run a regular (non-C type) TBird or a Duron on a KT133A/(other chipset) board?

That depends. Will a 100Mhz FSB CPU run on a KT133A set to 100Mhz? Absolutely. Will
a 100Mhz FSB CPU run on a KT133A set to 133Mhz? Not necessarily. Go here
for a discussion of this potential problem.

Before you buy a new motherboard, you should check to see if that board has such a problem. Probably the
best way to do this is to go here and type
in “{model number of motherboard} 100Mhz” and see what people have to say about it.

If you’re buying both a CPU and motherboard, you can avoid any potential problems simply by buying a 133Mhz processor.

Outside of that potential problem, once your socket A Athlon/Duron is unlocked, you should have
a fair amount of flexibility setting the FSB to 140Mhz or more. You’ll have
to adjust the multiplier accordingly – many chips will not simply tolerate a bump
from 100 MHz to 133 MHz at the same multiplier. Example: you have a 1 GHz “B”
(100/200 FSB) Athlon. Its default settings are 100 MHZ FSB with a multiplier of 10.
By unlocking the chip (see question 1) you should be able to run 133 MHz FSB and a
7.5x multiplier.

NOTE: This works only with Socket A chips running in these chipsets: KT133A, AMD
760 (DDR), SIS 735, KT266 (DDR), ALi Magik 1 (DDR) and any other chipset capable
of a REAL 133 MHz FSB. (Not KT133).

10. What is the “AMD recommended” list and how does it relate to me?

AMD has been very particular about their equipment – AMD’s techdocs outline many
parameters that a motherboard, heatsink, power supply, or other component has to
meet for it to garner AMD’s recommendation for use with their processors. AMD does
this in order to simplify hardware compatibility issues and potential problems
that enthusiasts and system integrators may have with AMD processors. The AMD
Approved list for components recommended for the Athlon can be viewed

Generally, parts that are approved for Athlon use are suitable for Duron use as

11. Why is my equipment not on the AMD recommended list?

Many parts, due to a problem of one type or another, are not recommended for use
by the general public with Athlon and Duron processors. This is an important thing
to consider when buying equipment, but take AMD’s recommendations with a grain of
salt. Do your homework, browse the forums at OVERCLOCKERS.COM and other hardware
sites, and find out WHY X Brand equipment is not recommended by AMD. Some things
that aren’t recommended by AMD are good to stay away from – e.g., the infamous
Orb series of CPU heatsink/fan units. Others, like the Abit KT7 series of
motherboards, are not recommended but many users find success with them. The best
thing to do when considering an equipment purchase is to find users who own/have
owned/use the equipment and listen to their experiences and opinions.

12. My motherboard manual says I should set my Athlon/Duron’s FSB to 100(133) MHz.

Yes, it probably does.

I thought the FSB was 200(266) MHz.

Yes, it is.

The AMD Athlon/Duron processor communicates with the northbridge using a DDR
(Dual Data Rate) bus. Hence the doubled MHz.

Most boards are designed to be compatible with both the “B” type (100/200mhz)
and “C” type (133/266 mhz) AMD socket A ( Socket 462) Durons and Athlons
(T-Bird) CPUs. The “B” type is “sold” to run at the 100 FSB speed. The “C” type
is “sold” to run at 133 FSB. While the board runs at 100 or 133 FSB, the CPU runs
at 200 or 266 due to it’s EV6 DDR architecture. Your Mobo allows you to run at
either CPU type at either FSB speed thanks to its mulitplier (frequency)
adjustments and FSB adjustments. However, you can’t run your “B” type at 266
without some modification. See Question 1.

13. How do I overclock my K6-X processor?

Generally, you overclock a K6 series processor the same way you would any other
processor. These chips are multiplier unlocked – as long as you have jumpers to
adjust the multiplier settings, they should work. Say you have a K6-2 450. The
default bus speed is 100 MHz and the default multiplier is 4.5x. The default
core voltage is 2.2v. Leave the core voltage at 2.2 volts to start and find your
next step up in cpu speed, e.g. 475 MHz (95 MHz FSB x 5 mult.). Set your jumpers
appropriately, boot the thing up and cross your fingers. If you get into Windows
successfully and are able to run some CPU-stressing programs without crashes, go
for the next step up in CPU speed. If you have stability problems or can’t get
into windows, up your core voltage and try again. And always watch temps. If you
don’t have temp monitoring hardware, put your finger on the HSF. If it’s too hot
to leave on there, you’re running too hot.

Here are some guidelines overclocking K6 series chips:

  • AMD’s techdocs state that 2.5V is the absolute maximum for these chips. A number
    of us have run up to 2.8-2.9V, but you’re moving into dangerous ground once you go to 2.5 or more.

  • Attainable FSB is about 112-115 MHz. A K6 chip won’t run much higher, as most
    motherboards don’t have a /4 PCI divisor.

  • K6-2 chips have a build in multiplier trick – setting the multiplier to 2x will
    actually yield a 6x multiplier.

  • Good HSF’s are abundant. Find the largest, chunkiest socket A HSF you can find
    and throw a decent 27 cfm or greater fan on it. And use thermal grease.

    The K6, K6-2, and K6-3 processors are close to max at the factory rating, so don’t
    expect to achieve very much from them. The “realistic” expectation is an extra
    50mhz – 100mhz Maximum… by raising FSB, crossing fingers, toes, etc….

    14. What are some things I can do to overclock my AMD X chip more?

    Well, you are usually held back by your weakest component, usually your RAM or
    video, possibly the NIC. You can try replacing them with good overclocking components. Remember
    that cooling is usually the biggest factor, so make sure that’s decent!!! You can cool your
    northbridge, southbridge, and clock generator, along with your RAM, and better
    cooling on the video card may also help.

    15. My socket broke. How do I fix it?

    You can try using superglue to attach the broken parts, but be advised that the
    socket material does not bond well with regular superglue, meaning it propably
    won’t last long under the pressure exerted by the heatsink clip/waterblock clamp.
    Best choice is to have a clamp made that uses the 4 holes around the socket to
    attach the heatsink or the waterblock. Another is to buy a heatsink/waterblock
    that is designed to use the 4 surrounding holes. If you’ve only broken the center
    tab, there are several good heatsinks available that clamp on both (or all three)
    socket tabs. Also, see this article by John “Hoot” Hill, the
    AMD CPU’s, AMD Motherboards and Cooling forums Moderator.


    N2 and


    16. What are these CPU codes and what do they mean to me?

    When people refer to an Athlon or Duron’s “code” they are referring to the 4 or 5
    letters written on the second line of the CPU core. Overclockers have found these
    to be useful in identifying batches or chips that tend to overclock better than
    others. The first character on the third line can also be an indicator. At the
    time of writing, the primo codes for Duron are AKBA and AKCA. For the Athlon,
    look for AXIA-Y, AHYJA-Y, AXIAR-Y, and AHYJAR-Y. Some also claim the AVIA-Y chips
    to be primo overclockers. See also this matrix.

    17. What’s the difference between all these different types of “Athlons” I see/hear about?

    The original “Athlon” was a chip initially manufactured under a .25u process and had 512 KB
    of on-chip cache, running at either half or 1/3 processor speed. It utilized a
    connector dubbed “Slot A” which was actually just Intel’s SECC connector turned
    backwards. Chips are no longer made for this platform; chips are available from
    500 MHz to 1 GHz.

    The “Thunderbird” is the next type of Athlon. It is manufactured
    under .18u process and features 256 KB of on-die cache that runs at full CPU
    speed. This sped that Athlon up greatly. The Thunderbird also marked the
    beginning of the Socket A platform, though a few Slot A Thunderbirds were produced
    for OEM’s and are compatible with AMD 751 chipset motherboards. At the time of
    writing, the Thunderbird is available from 650 MHz to 1.4 GHz, and is not
    expected to be introduced at any higher speeds, due to core limitations and
    cooling issues.

    The “Duron” is AMD’s value Athlon. It features the same core logic as the
    Thunderbird but has only 64 KB of full speed L2 Cache compared to Thunderbird’s
    256 KB. The Duron is a legendary overclocker and is notorious for trashing its
    Celeron counterparts, clock for clock, in addition to being less expensive. The
    Duron we have grown to know and love has a codename of Spitfire for the current
    core. Durons have dropped to astronomically low price levels and are great chips
    to stick in the “Grandma” system now that motherboards with integrated video,
    sound, modem and NIC are available for socket A. The Spitfire cored Duron is
    available in speeds from 600 MHz to 950 MHz.

    At the time of writing, the next generation Duron has debuted at 1 GHz and
    has the same core logic as the next generation of Athlon and has the codename
    “Morgan”. Morgan features SSE optimizations, a larger Translation Lookaside
    Buffer, and hardware instruction prefetch. This chip will be known in retail
    channels simply as the Duron but take note, it has many differences between
    itself and the previous (950 MHz and lower) Durons. This chip is also rumored to
    be multi-processor (SMP) capable. Morgan starts at 1 GHz and is expected to ramp
    to 1.5 GHz before it is replaced.

    The Athlon “MP” is AMD’s first attempt at a server-oriented chip. The MP is based
    on AMD’s Palomino core and features the SSE optimizations, larger TLB and
    hardware prefetch mentioned about Morgan in the previous paragraph. The MP is
    designed to work in multiprocessor servers and workstations and peforms admirably
    in such applications. Currently the AthlonMP is available in 1 GHZ and 1.2 GHz
    parts and is expected to ramp to around 1.9 GHz.

    The yet-to-be-released desktop version of the Palomino will have many of the same
    features as Morgan, but with larger L2 cache. It is not yet known what name this
    chip will bear in the retail channels, speculation is the ‘Athlon 4 Desktop’ or
    even the ‘AthlonXP’. Many speculate this chip to be introduced at 1.4 GHz and 1.53
    GHz speeds and ramp to around 1.9 GHz.

    18. What are acceptable temperatures AMD Athlons/Durons? How do I view them?

    You can view your temps in your BIOS under the “Hardware Monitoring” or “PC
    Health Status” sections or in Windows through a program such as Motherboard
    Monitor 5, which is available here.

    Most of us forum dwellers have come to this consensus on AMD chips:

    Idle Temperatures:

  • < 20 C: Who the heck are you and what are you using? Liquid N2?
  • 20-35 C: Normal and acceptable for high end aircooling
  • 35-45 C: Getting a little on the sweaty side of normal, but par for typical
    generic aircooling solutions.

  • 45-55 C: You’re definitely doing something wrong, especially if you’ve got a nice
    high end heatsink. Look into it.

  • > 55 C: You’ve got serious problems…..

    Load temperatures:

  • < 30 C: You're working magic
  • 30-45 C: Good Job. You’re normal and very safe
  • 45-55 C: A mite high, but normal for low end/generic aircooling. You might
    experience an occaisional lockup or two but you’re still OK for the most part.

  • > 55+ C: You’re going to be experiencing frequent lockups and other problems.
    Look in to nicer cooling solutions or take that overclock down.

    Keep in mind that these are all relative…. I’m assuming most of you have your
    computer room in a 20 to 25 C environment. Case cooling also has a big impact on
    your CPU temps.

    19. Why can’t I go over xxxMHz FSB?

    If you have a Via KT133 or KX133 chipset, see question 2. Otherwise, attainable FSB
    speed is dependent entirely on the highest FSB your CPU, PCI devices, and IDE
    devices can collectively take. Many AMD overclockers have attained FSB’s up to 170
    MHz. Usually this requires a motherboard with a 1/5 or 1/6 PCI divisor and some
    serious northbridge cooling.

    20. What are the VIA 4-in-1 drivers? Where can I get them? Which version should I use?

    The VIA 4-in-1 drivers are specific to motherboards that use VIA chipsets, eg.
    MVP3, KX133, KT133(A), KT266. They contain drivers for the IDE controller, USB
    controller and an AGP GART.

    You can find the VIA 4-in-1 drivers from VIA’s homepage.
    VIA Hardware, Via Hardware also has 4-in-1 drivers, often newer
    (beta) versions.

    There is no “best” version, but usually the latest revision of the 4-in-1
    drivers is the best bet. The newest beta version is 4.33 and the newest
    official version is 4.32, at the moment of writing.

    21. My computer hangs when using Athlon, Windows 2000 and a program that uses AGP, how do I fix this?

    The Microsoft Knowledge Base, Q270715 has a detailed explanation of the problem
    and also has a solution for it. See it here


    N2 and


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