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K6-2 Upgrade

Upgrading Older Systems
To AMD's K6-2 Processor with 3DNow! Technology


AMD's Socket-7 K6-2 processor is an upgrade option for many existing non-MMX and MMX Pentium systems and motherboards (even really old Socket-5 motherboards), and offers significant performance improvements, compared to older Pentium, and even newer, Pentium MMX CPUs.

The Problem:

Unfortunately, there are two problems with simply dropping a K6-2 into a normal Pentium motherboard. First of all, older non-MMX Pentium motherboards do not support split voltages, which means that dropping a K6-2 directly into an older Pentium motherboard would most likely fry it. Second of all most non-MMX motherboards (and some MMX motherboards too) do not support high enough multipliers to run a K6-2 at a 66MHz bus speed, which is the highest bus speed that older motherboards support.

The Solution:

Two products, Powerleap's PL-ProMMX CPU Upgrade, and Concept Manufacturing's CM-VAK6-2 slip-on voltage regulator kit, allow older motherboards to overcome those problems by provides full electrical and clock multiplier support for the AMD K6-2. Both of these products overcome the limitations of existing motherboards that don't meet the minimum specifications as defined by AMD to support the K6-2.


For a list of systems and motherboards that are known to be compatible with the K6-2, see Powerleap's Compatibility List. Systems listed there are upgradeable using the PL/ProMMX or the CM-VAK6-2 with the AMD K6-2 266/300 MHz CPU without a BIOS upgrade.

BIOS Issues:

As you might expect, there are some BIOS issues when considering the AMD K6-2 as an upgrade.  Systems listed as "K6 Compatible" on Powerleap's Compatibility List don't require a BIOS upgrade.  For systems not on the list, generally any system or motherboard with a BIOS version listed below can be upgraded to the K6-2 without the need for a BIOS upgrade:

  • Award: Compile Dates of March 1, 1997 or Later
  • AMI: CPU Module 3.31 or Later
  • Phoenix: Version 4.0, Release 6.0, or Release 5.1, with Build Dates 4/7/97 or Later

Where a BIOS upgrade is needed, K6-compatible BIOS upgrades from AMD are available for many existing systems.

The Units:


Key Features:

  • Works in Socket 5 and Socket 7 systems, regardless of electrical limitations of the motherboard.

  • Patent Pending Technology:

    The PL-ProMMX incorporates an new method of supplying power to the CPU that bypasses the electrical power circuitry of the host motherboard. This allows low-voltage MMX processors to run in non-MMX motherboards without overloading the motherboard's electrical system. Without this unique design, component overheating and motherboard failure are the likely outcomes.

  • Exclusive AMD K6-2 Support!

    Even if your motherboard or system manufacturer says that your PC isn't K6-2 compatible, the PL-ProMMX overcomes all electrical and clock multiplier barriers!

  • A complete CPU upgrade kit.

    Fully illustrated installation guide. High-Performance Heatsink and ball-bearing fan included. 3-year warranty. Free telephone technical support (1-877-CPULEAP). 24-hour tech support via the Internet.

If your system is: Then Your System Bus Speed is: The Speed of Your System After Upgrading with PL/ProMMX + AMD K6-2:
K6-2 266 CPU: K6-2 300 CPU: K6-2 333 CPU:
Pentium 75 50 MHz (see note below)
250 MHz (5x)
275 MHz (5.5x) 275 MHz (5.5x)
Note: Pentium 75 MHz systems have a 50 MHz system bus speed, which limits the final speed of the CPU upgrade.  Notice in the above chart, for example, the K6-2 266 runs at 250 MHz instead of 266 MHz.   Many systems have a jumper to change system bus speed to 60 or 66 MHz for optimal performance. If you can change your system bus to 60 MHz, then your upgrade speeds would be the same as for a Pentium 90 (below).  If you can change your system bus to 66 MHz, then your upgrade speeds would be the same as for a Pentium 100 (bottom).
Pentium 90, 120, 150, 180 60 MHz (see note below) 270 MHz (4.5x) 300 MHz (5x) 330 MHz (5.5x)
Note: A 60 MHz system bus speed may limit final upgrade speed.  Many systems have a jumper to change system bus speed to 66 MHz for optimal performance . If you can change your system bus to 66 MHz, then your upgrade speeds would be the same as for a Pentium 100 (below).
Pentium 100, 133, 166, 200 66 MHz 266 MHz (4x) 300 MHz (4.5x) 333 MHz (5x)

Socket 5 Support
Socket 7 Support


Concept Manufacturing's CM-VAK6-2 slip-on voltage regulator kit allows the voltage on your existing Socket 7 motherboard to be adjusted to accept and upgrade to the new AMD, K6-2(3D) microprocessor. Basically, the kit converts the existing core voltage in an MMX motherboard from 2.9 or 2.8 volts to 2.2 volts. There are no jumpers to set and no software to load or reconfigure. What's more, installation time takes less than five minutes once the cover is removed, and the kit comes with a one-year limited warranty.

Use Your Existing PC

Your existing system is upgradeable to the new AMD K6-2 microprocessor using the CM-VAK6-2 voltage regulator kit to frequencies of 333MHz and beyond. The kit has a built-in clock multiplier that overrides the motherboard clock multiplier and will allow the upgrade microprocessor to function at full speed in the Socket 7 CPU location. The kit also includes a fan/heat sink to meet the K6-2 thermal requirements at no extra cost.


1. The CM-VAK6-2 requires an MMX motherboard with 3.3 I/O volts and 2.9 or 2.8 core volts. K6-2 frequency upgrades apply from 233MHz to 333MHz and beyond. The motherboard must contain a "switching regulator" for application of the K6-2 processor at 300MHz and beyond (the switching regulator position on the motherboard may be recognized by a small heat sink and a copper-wound coil).

2. On a non-MMX motherboard with 3.3 volts (and no voltage regulator), the maximum K6-2 frequency upgrade with the CM-VAK6-2 is 266MHz.

Unlike the PL-ProMMX, the CM-VAK6-2 requires that the motherboard must have a Socket 7 compatible slot (no Socket 5 support).

Quick and Easy Installation

Installation takes less than two minutes once the cover is opened. There are no jumpers to set and no software to load. Just remove your computer's cover and follow the Assembly Instructions.

Socket 7 Support
No Socket 5 Support

Performance Issues:

As we all know, the K6-2 was specifically designed for a 100MHz front side bus. It will work at lower bus speeds, such as 66MHz, however, performance may be decreased. Since almost all older motherboards support bus speeds of only 66MHz or lower, some performance issues may arise. To get a good estimate of how much performance you will be losing by running your K6-2 in an older motherboard, we can take a look at this benchmark chart: 

This test was run using a Soyo 5EHM with a K6-2 at the different bus speeds listed above. The performance of the K6-2 in an older motherboard would be slightly lower than the very lowest score on that chart. The loss isn't really too huge (only about 2 fps in Quake II which is no big deal), but it is something you may want to take into consideration.


Both of these products can be purchased online, directly from the manufacturer.

Powerleap's adapter can be puchased individually for $54.95 from The adapter can also be bundled with a K6-2 300MHz for $199.99 or 333MHz ($249.99) CPU

Concept Manufacturing's adapter can be puchased individually from for $49.95.

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