M571 Upgrades

M571 based computer systems can still provide useful service in today's personal computing environment. This page is a collection of tips for upgrading M571 3.2, 3.2a, and 7.0 boards. One needn't be an "expert" to achieve satisfactory results! I gratefully acknowledge Brad's and Jim's input to this page. Many M571 users have profited from their well-informed and patient advice on the EYO Tech Forum, including myself.

Download and read the Manual first!

M571 Manual (.pdf)

Quick links to related subjects referred to on this page:

Jumper Settings






A graphic overview of M571 jumper settings and functions

Processor guide






A tabulation of AMD processors suitable for M571 boards

timmy's M571






What I've done to my M571 3.2, including benchmarks

USB and J7






Setting up USB on the M571, and J7 pinouts

Tweak Guide






BIOS tweaks for more performance

Video Guide






Selection and tweaking video cards for the M571

Memory Guide






Selection of M571 System Memory


Video Board Upgrades

My own tests show that memory performance suffers approximately 30% by using the onboard video function as opposed to using any PCI video card. The question then becomes, what video board should be used to upgrade an M571 system? See the M571 Video Upgrade and Tweaking Page.

Memory Upgrades

The amount and properties of memory strongly affect the performance of M571 based systems, just as this critical system resource affects any computer. But certain guidelines should be considered when selecting and installing memory. Consult the M571 Memory Page to understand how to maximize your M571 system memory performance.

Processor Upgrades

This section focuses on AMD K6 2 and K6 3 processors as upgrades for M571 based systems. They are the most powerful Socket 7 processors available and M571s using one of these chips can still be used for most computing applications. Gamers who still have old K6, Cyrix, and Pentium chips on their M571s will experience greatly increased multimedia performance when switching to a K6 2 or K6 3, due to these processors having incorporating MMX and 3D Now! instructions.

Computer users often become dedicated devotees of one type of processor or another. Consider these words from an article posted on "Lost Circuits":

"As stated in an earlier review, the difference between the K6-III and its shrunk version on the one side and any other CPU out there is the incredible crispness of its operation. That is, in multitasking situations, there is hardly any CPU that switches as smoothly between windows as the K6-III. This is certainly worth a consideration when raw performance is not the only criterion. In the world of CPUs, if there is any analogy possible, the K6-III would be a 2-stroke street bike. There are faster things in the world but hardly anything beats the bite of the last Sharptooth."

Lost Circuits, July 13, 2001

M571 boards are Socket 7 based designs that were initially intended to (in the 3.2 version) support 233 MHz processors at Socket 7's standard Front Side Bus rate of 66 MHz. Significant performance increases can be realized through a processor upgrade and, if well executed, will make your machine behave like a new one!

(Note: 3.2, 3.2a, and 7.0 boards can be set to provide 75 MHz or 83 MHz Front Side Bus rate. System stability at these settings must be determined on a case-by-case basis.)

While every effort has been made to point out how modifications can enhance the usefulness of M571 systems, I cannot take responsibility for what the implementation of these tips may cause on any particular computer. Please note that, as with modification of any device, the understanding and craftsmanship of the modifier is crucial. It is highly recommended that any potential modifier have a basic understanding of the technical issues they are dealing with before making these modifications.

What is the difference between the AMD K6 2 and the AMD K6 3?

The AMD K6 3 design includes an "on-board" 256 KB Level 2 cache that is not present on K6 2 chips. This cache supplements the on-board 64 KB Level 1 cache. The former L2 cache on the M571, running at front side bus speed, becomes a Level 3 cache when a K6 3 chip is used. The K6 3's on-board Level 2 cache provides increased performance over the K6 2. Expect a performance difference between K6 2 and K6 3 chips running at the same speed of approximately 20%, or expect that a K6 3 400MHz chip will perform roughly similar to a K6 2 500 MHz chip. These comparisons will vary depending upon the particular applications that are being run on a given system.

One other advantage offered by the K6 3 chip is the ability to effectively use more system memory, or RAM. The M571 L2 cache is 512 KB in size, and can cache only 128 MB of system memory. Using more memory than this can result in LESS performance, because Windows will be using memory in the uncached area.

A K6 3 processor's on-chip 256 KB L2 cache can effectively use up to 4 GB of system memory, or RAM! Officially, M571 systems do not support DIMMs greater than 64 MB, but some 128 MB DIMMs will work. An M571 with a K6 3 processor can then effectively use a total of 256 MB of system memory. Windows 9x/ME does not usually benefit from memory beyond 128 MB, but if you are running Windows 2000 or Windows XP, you may need the 256 MB capability that a K6 3 can support. The cache on the M571 motherboard, which becomes L3 cache when a K6 3 is installed, will still only cache 128 MB of system memory. Using system memory above 128 MB may be 1% or 2% slower than a similar system with 128 MB or less, but this is not generally apparent. The memory performance increase available from a K6 3 is still greater than any other processor, regardless of the amount of memory installed.

A personal note about the K6 3:

The K6 3 is a great processor. Like another great AMD processor, the 386-40, it offered performance beyond what was available or expected from similar products of other manufacturers. Many experienced users still have a high regard for them, even though their technical heyday has passed. Some feel there is a certain "mystique" about owning and using one. Whether you feel this way or not, I'm sure you won't regret running one if you have the opportunity.

Where can AMD K6 3 processors be found?

AMD no longer makes the K6 3 line of processors and the K6 3 mobile processors were usually sold only to laptop manufacturers, so finding a suitable K6 3 can present a problem. Some chips have come on the market as surplus stock from vendors of processor upgrade devices. Searching EBay for "AMD K6" is one possible source. These chips may be surplus stock or ones removed from an existing system, so one is often on their own for guarantees and support. As a rough idea, K6 3s can range in price between $50 and $100 USD on ebay. Pricewatch (www.pricewatch.com) occasionally carries K6 3 chips ranging from $40 to $60 USD. Recently, the Fry's Electronics chain has been selling 333 MHz K6 3 chips for $20 USD, although every store does not have them. I obtained one and installed it on an M571 3.2a, replacing a K6 200. It was $20 well spent!

K6 2s can be found at dealers and at the same sources listed for the K6 3. My latest checks indicate that $25 to $30 USD is a reasonable price range for a K5 2 500 MHz chip.

K6 2 and K6 3 processor guide

AMD made many different K6 2 and K6 2 mobile processors that can be used on an M571 board. Also, K6 3 processors came in standard and mobile versions. Several core voltage levels were also supported, which is a key consideration when upgrading an M571.

For a more detailed picture of K6 2 and K6 3 models that will help you to choose which chip may be most suited to your M571 upgrade, please click this AMD processor guide: timmy's AMD processor guide. Power consumption and heat generation issues are addressed in this guide, so check out the guide for information on these important topics.

What processor speeds can be achieved on the M571?

The speed at which the processor runs is determined by the Front Side Bus speed, set by JP5 A, B, and C jumpers, times the multiplier factor set by JP7. The board is normally set to run at or below the processor's speed rating in MHz. The following table lists possible processor speeds above 266 MHz:


Bus Speed

Clock Multiplier

------66 MHz------

------75 MHz------

------83 MHz------


266.7 MHz

300 MHz

333.3 MHz


300 MHz

337.5 MHz

375 MHz


333.3 MHz

375 MHz

416.7 MHz


366.7 MHz

412.5 MHz

458.3 MHz


400 MHz

450 MHz

500 MHz

Note: 75 MHz and 83 MHz Front Side Bus speeds may or may not be stable on any given system.

The AMD K6 2 and K6 3 CPUs are rated at 100 MHz front side bus speed. Will they work with my M571?

Yes. Most K6 2 and K6 3 processors are rated at 100 MHz front side bus speed, although some are only rated at 95 MHz. Because either rating is far greater than the M571 front side bus speed settings of 66.7, 75, or 83.3 MHz, that side of the processor will be underclocked and work fine. You can run a K6 2 or 3 at any of the front side bus speed settings without stressing the chip.

Is there an advantage to setting JP5 to provide a front side bus speed of 75 MHz or 83.3 MHz?

Yes, if the other components in your system will handle the increased speeds that this change will cause. Not only can you run the CPU faster than 400 MHz, but many other processes in your system will be accelerated by such a change. The front side bus is the means by which the CPU communicates to the rest of the system through the chipset. This includes the PCI bus, the IDE drive interfaces, and the system memory.


One of the most important changes will be faster access to system RAM, or memory. Some of you may remember that when Intel brought out the first 486 processors, they ran at 25 MHz and 33 MHz, and used the same front side bus speeds. AMD, Intel’s competition, did not have a 486 design to compete with the new Intel chip, so they increased the speed of their 386 CPU to 40 MHz. Many users of the AMD 386 40 systems (including myself) were delighted to find that their inexpensive 386 based system could rival, and in some cases, even exceed, the performance of the new 486 based systems, due to the increased memory performance that the 40 MHz front side bus provided. By increasing your M571’s front side bus speed to 75 MHz, or even 83.3 MHz, you will also experience a very tangible increase in your system’s performance.


However, not every M571 based system will respond favorably to increasing the front side bus speed above 66 MHz. Study the following sections to understand whether your system could take advantage of a faster bus speed, and how you might accomplish this change.


What about AMD chips and the problem with JP5 D?

JP5 D sets the speed of the PCI bus, to which the first four expansion slots are connected on an M571 board. This bus is specified to run at 33 MHz. JP5 A, B, and C set the speed of the Front Side Bus, which is what the processor uses to access system memory and L2 cache.

(Remember that Level 2 cache becomes Level 3 cache when a K6 3 is installed. Because a K6 3 can access its onboard L2 cache at processor speed, e.g., 400 or 450 MHz, it performs much faster than a processor that must access L2 cache via the 66 MHz Front Side Bus.)

JP5 D determines whether the speed of the PCI bus is set to 1/2 the speed of the front side bus (JP5 D pins 1 & 2 jumpered) or whether it is set to 2/5 the speed of the Front Side Bus (JP5 D pins 2 & 3 jumpered).

For Front Side Bus speeds up to 66 MHz, PcChips specifies jumpering JP5 D pins 1 & 2 to run the PCI bus at 25, 27.5, 30, or 33 MHz, depending on the value set by JP5 A, B, and C. However, selecting a front side bus of speed 75 MHz runs the PCI bus at 1/2 of 75 MHz, or 37.5 MHz. This may cause errors with PCI expansion cards designed for 33 MHZ operation. Version 3.2a and 7.0 boards running at 83 MHz are an even greater issue, since this setting would run the PCI bus at 1/2 of 83 MHz, or 41.7 MHz. PcChips therefore provides the JP5 D pin 2 & 3 setting, which sets the PCI bus to run at 2/5 of the Front Side Bus speed.

Even though other chips do not have a problem running the PCI bus independently of the Front Side Bus, AMD processors do. The K6 2 and K6 3 need to have the PCI bus clocking one "tick" for every two "ticks" of the Front Side Bus, or the system will very likely not even boot. Picture this example of the PCI bus speed set to 1/2 of the 75 MHZ Front Side Bus speed (JP5 D set to pins 1 & 2) Notice how there is a Front Side Bus "tick" for every PCI bus "tick":

l--------l--------l--------l--------l--------l Front Side Bus "ticks"

0--------------15--------------30-------------45--------------60-------------75 (units of time)

l-----------------l-----------------l-------- PCI Bus "ticks"

0--------------------------------30-------------------------------60-------------- (units of time)

Now, picture the problem when the PCI BUS is set to 2/5 the speed of the Front Side Bus speed of 75 MHz (JP5 D set to pins 2 & 3). Notice how every other "tick" of the PCI bus occurs without an accompanying "tick" of the Front Side Bus, causing an unsynchronized condition between the Front Side Bus and the PCI bus:

l--------l--------l--------l--------l--------l Front Side Bus "ticks"

0--------------15--------------30-------------45--------------60-------------75 (units of time)

l---------------------l---------------------l PCI Bus "ticks"

0---------------------------------------37.5-------------------------------------75 (units of time)

Set JP5 D to jumper pins 1 & 2 on M571 3.2, 3.2a, and 7.0 boards with K6 2 and K6 3 chips, regardless of the manual's instructions. A side benefit is that overclocking the PCI bus will provide a boost in performance - you will notice that your video response is especially speedy! Remember that operation of PCI cards above 33 MHz can cause unreliable operation and card failure. Furthermore, problems at 83 MHz Front Side Bus speed may not be present at 75 MHz.

If all of this seems to be confusing, keep in mind that even a 400 MHz K6 2 processor will provide a good boost over the 300 MHz or less processor you may be using now. 450 MHz is obtainable from most systems and it may be possibile to reach 500 MHz. AMD K6 2 500 cpus are still very reasonably priced and available. I recommend getting a 500 or better if you want a K6 2, since slower chips are seldom much cheaper, and the ability to run the chip up to 500 MHz may be appreciated later.

Can PCI cards work at 37.5 and 41.7 MHz?

Yes, in many cases. One of my personal systems is running at 83.3 MHz front side bus and 41.7 MHz PCI bus speeds. I am using an SMC ethernet PCI card, which has given completely reliable service. I have not found any problems with an ATI xpert@play or an ATI Radeon video cards using the 41.7 MHz speed. However, my Soundblaster Live! Value sound card was another matter.

Overclockers seem to agree that the Soundblaster Live! Value gives trouble at PCI bus speeds faster than 33 MHz. My own card worked well at 33 and 37.5 MHz, but would lock up the system at 41.7 MHz. To solve this problem, I obtained a 40 mm heatsink/fan meant for a 486 cpu. The Soundblaster processor chip is 20 mm square, but the 486 cooler was the smallest one I could find. I carefully studied the Soundblaster card for components that would prevent the 486 heatsink from completely contacting the Soundblaster processor. Several components were identified, so I relieved about 5 mm of one edge of the heatsink to a depth of 1 mm with a file. Heatsinks are anodized and surprisingly hard; a good file was needed for this process. I attached the heatsink to the processor with a small amount of Arctic Silver epoxy and connected the fan to 12 volts. The Soundblaster board now operates properly at the 41.7 MHz speed.

This experience is standard overclocking procedure and is mentioned to demonstrate that overclocking problems often have solutions. If some of your components cause problems when used on a fast PCI bus, try to identify what is casing the instability and attempt your own solutions. Sometimes it is possible to slow down your system in conjunction with removal of components to isolate the problem. Fast systems generate more heat, so keeping everything cool inside the case is always a good idea. When you attempt modification, you are assuming your own risks. You should understand that your solution may not work or may cause component failure before you begin.

Are Hard Drives affected by increasing the front side bus speed?

Sometimes - yes. Increasing front side bus speeds to 75 MHz or 83.3 MHz can greatly improve system performance, but remember that the IDE controller is accessed through the PCI bus and is also affected by the front side buys speed, just like PCI cards. Older drives may cause data corruption when the PCI speed is raised to 41.7 MHz. If your hard drive is affected by high bus speeds and you are determined to run your system at higher speeds, a hard drive cooling arrangement may allow a finicky hard drive to work.

How do I achieve a 6x multiplier setting on AMD K6 2 and AMD K6 3 processors?

The highest multiplier documented on M571 boards is 5.5x. However, a clock multiplier setting of 2x is interpreted by K6 2 and K6 3 chips as 6x. For example, a Front Side Bus setting of 66 MHz and a multiplier setting of 2x would provide a processor speed of 400 MHz (6 x 66 MHz = 400 MHz). Similarly, a Front Side Bus speed of 83 MHz and a multiplier setting of 2x would result in a processor speed of 500 MHz (6 x 83 MHz = 500 MHz).

Can the speed set on the M571 exceed the processor's rated speed?

Yes - but not always successfully. This condition is called "overclocking". Overclocking can result in overheated processors that burn out and unstable operation. Overclocking can also support stable platforms providing a useful upgrade in their own right. One should study overclocking thoroughly to understand the risks and advantages. It is possible to set an M571 to run processors at many speeds up to 500 MHz, by the use of JP5 and JP7, but the system may not work. Getting a processor to run faster than its rated speed may not be possible or may call for other measures.


Generally speaking, one may expect approximately 450 MHz from a K6 3 chip. 2.4 volt "AH" series chips are considered harder to overclock than 2.2 volt "AF" versions. The K6 3 450 was made using a different production process than the slower cpus were, and are the best opportunity to achieve 500 MHz. I have personally had no problems operating K6 3 333 and K6 2 333 cpus at 400 MHz (66.7 x 6 = 400 MHz).


Keeping the processor cool is always helpful when trying to operate a cpu faster than its rated speed. This can be achieved by using heatsink-fan cpu coolers with a greater ability to radiate the addtional generated heat. Study the heatsink you buy carefully: Some may have the fins blocked by motherboard components, especially if a long video card is used in PCI slot 1. For those who are pursuing speed increases beyond the ragged edge, water cooled cpu heatsinks are available, or can be fabricated.


Raising the core voltage may also help achieve system stability at overclocked processor speeds, and this subject is covered in more detail below.


Previous paragraphs have dealt with increasing the M571's board operating speed. The following paragraphs address speeding up the CPU chip itself.

What is "core voltage"?

Chip manufacturers found that higher speeds were achievable by basing their designs on thinner layers. These thinner layers required lower voltages, which results in lower heat, lower power consumption, and lower operating voltage for the same processing power. Socket 5 boards ran the internal core of the chip at the same voltage as the board: 3.3 volts. Socket 7 boards, like the M571, include a voltage regulator to provide reduced voltage for the cores of the new processors built with thinner semiconductor layers. Processor core voltage is set by JP6 jumpers on the M571.

What if JP6 core voltage settings don't match chip specifications?

This situation often occurs with the M571 3.2. The lowest factory documented core voltage setting is 2.5 volts. With a large cooling fan, one might or might not be safe in using an "AH" 2.4 core voltage chip with a setting of 2.5 volts.

M571 3.2a and 7.0 version boards provide a 2.2 voltage setting, which may not be appropriate for some AMD chips requiring higher or lower settings.

Finally, some 3.2a and 7.0 boards will not operate reliably when set to 2.2 core volts, because the regulator is actually not providing a true 2.2 volts to the chip. AMD K6 2 and K6 3 processors can be sensitive to low voltages and operate unreliably under such conditions.

The jumpers of JP6 are used to configure a resistive network that "tells" the M571 core voltage regulator how much voltage to provide to the processor socket. Therefore, by changing the resistive characteristics of the control network with JP6 jumpers, it is possible to provide the standard core voltage to the chip.

How is the M571 configured to achieve non-standard core voltages?

3.2 version: Obtaining voltages below 2.5v

M571 3.2 boards can achieve a 2.2 core voltage level by connecting a 39K ohm resistor from one of the inner (that is, farthest from the edge of the board) pins on JP6 to ground (pin 3 of the speaker connector [on J3], pin 5 of the keyboard lock connector [on J3], and pin 3 of the power fan connector [J2] are all grounds). An error in this process can result in unpleasant consequences, so make sure you know what you are doing. A 2.3 core voltage setting can be achieved by using a 62K ohm resistor in place of the 39K resistor, and a 2.4 core voltage level can be obtained by using a 120K ohm resistor in place of the 39K ohm resistor. Consult Franc Zabkar's excellent work on 3.2 core voltage settings at: franczabkar/v32corev.htm

3.2a & 7.0 version: Obtaining voltages below 2.2v

M571 3.2a and 7.0 boards can be modified in the same way for a 2.0 core voltage level. (These boards come with a 2.2 core voltage level from the factory.) Connect a 47K ohm resistor as described in the 3.2 section, above. For 1.9 core volts, use a 33K ohm resistor and for 2.1 core volts, use a 100 K ohm resistor. Consult Franc Zabkar's very useful 3.2a and 7.0 notes on core voltage at: franczabkar/v70-20v.htm

3.2a & 7.0 versions: Obtaining voltages between 2.2v and 2.8v

3.2a and 7.0 boards may pose problems when the 2.2 core voltage level is selected. The 2.2 volt setting can be very close to what a K6 2 or K6 3 chip needs to operate reliably. Often, raising the core voltage by .1v or .2v will fix this problem. It is highly suggested that, if you have performed an upgrade and are having troubles leading you to suspect that the 2.2 core voltage setting is not providing sufficient voltage for proper operation, you check core voltage at this point with a reliable VOM before proceeding with a "fix".

Fixing this sort of trouble requires attaching an additional resistor across the pins at the 2.8 core volt jumper setting; that is, instead of jumpering the 2.8 volt setting, a resistor needs to be connected across those two pins instead. On 3.2a and 7.0 boards, connecting a 120K ohm resistor across the 2.8 volt pins will give approximately 2.3 volts, or a .1 volt increase over the 2.2 volt setting. Since the 2.2 volt setting may not supply enough voltage for a 2.2 core voltage chip, this may correct the problem. Additionally, using a 47k ohm resistor at the 2.8 volt jumper will give a .2 volt increase and a 22K ohm resistor will give approximately a .3 volt increase.

This corrective process on 3.2a and 7.0 version M571 boards is offered to the thoughtful craftsman who takes time to use correct tools and do a job correctly. This includes checking core voltage levels after making each change to achieve precise settings. Again, Franc Zabkar has done most of the thinking work to solve this problem and offers detailed analysis of the low 2.2 volt problem at: franczabkar/voltcore.htm

Use connectors that facilitate reliable and simple connection of resistors to these pins. I strongly advise against trying to solder to the pins on the board.

How is the core voltage checked with a volt ohm meter (VOM)?

A core voltage measurement can be obtained by connecting a VOM to JP8, jumper A, pin 3 and to ground, such as pin 3 of J2, the fan power connector. You must use a digital VOM -- older analog VOMs are not accurate enough for this measurement and their low input resistance will load the circuit, causing a false reading. The voltage at the actual processor pin will be a small amount (~ 50mv) less due to loss on the board circuitry. Remember that it is very easy to short something out when checking with metal test probes and the low voltages involved may not provide a notifying arc. Shorting components may be destructive. Measurements can be made safely if one is careful, but anyone performing these activities does so at their own risk. Make sure you know what you are doing!

Again, consult Franc Zabkar's fine notes on core voltage measurement at: franczabkar/pwrnotes.htm

You must have a load on the core voltage regulator to obtain an accurate reading. I checked the core voltage after modifying my board with the old processor in the socket. It may not give the same reading as the new processor, but you will at least know if you are close to the correct setting without burning the new processor up! My core voltage did not change between old and new processors.

Must the core voltage setting match processor specifications?

It is usually best to match the core voltage to AMD's specifications. AMD processors have a .1 volt tolerance, plus or minus, from the nominally specified core voltage. Core voltages higher than specification produce more heat and can damage the chip, while lower voltages can result in unstable operation. It is always the individual's risk to disregard the manufacturer's specifications. That said, higher core voltages, along with high capacity cooling fans, are often used when overclocking a system.

Sometimes, the core voltage must be increased beyond rated values to make an overclocked processor stable. The amount of increase a specific chip can withstand without failure must be determined by experimentation, This entails a risk which increases as the voltage is increased. Many experienced overclockers agree that 2.6 to 2.7 volts is the maximum that any K6 2 or K6 3 can stand. Some will fail at these voltage levels. Most useful processor speed increases are achieved below the range of 2.6 to 2.7 volts.

One of my systems was stable at 458 MHz and 2.28 core volts using DOS based Windows operating systems, but became unstable when Windows 2000 was installed. I increased the core voltage to 2.35 volts, which has made the system stable. Apparently, Windows 2000 places loads on processors that DOS based Windows does not. (This seems reasonable, since Windows 2000 offers increased system performance.) Whether this setting truly exceeds the 2.3 upper voltage rating of the chip is questionable, since there may well be .05 volts of loss between the measurement point described on this page and what is actually delivered to the processor core.

Remember that cooling becomes more critical as overclocking increases the heat output of a cpu. The 2.4 volt "AH" series, especially, can produce prodigious amounts of heat as the core voltage is raised. Some users remove the aluminum cover to cool the actual cpu chip more effectively. Prying the aluminum cover from the chip is a delicate task that is not for the faint of heart, and does not seem to offer a great deal of advantage. Try this method at your own risk.

Do you have any personal experience with M571 upgrades, timmy?

Please check out a description of my systems here: timmy's M571s with K6 3 400, K6 3 333, and K6 2 333

What if I'm using Windows 95?

Windows 95 requires a special patch when used with AMD processors above 350 MHz. This patch is described on the AMD site at: http://www.amd.com/products/cpg/k623d/win95_update_k6.html

Read the description very carefully before downloading and installing the patch.

My personal opinion is that Windows 95 OSR 2 is still viable in some instances. However, it takes some degree of commitment to make this OS operate correctly. Upgrading drivers can take some time. For instance, upgrading the Dial Up Networking drivers (DUN) to the 2.0 level and increase modem performance considerably. This site should be considered a must for checking out the revision levels of your Windows 95 drivers: Windows 95 System Updates

Windows 95 runs fairly quickly and is more compact on the hard drive. It does not manage memory particularly well, nor is it as stable as later Microsoft OSs. However, If you have some compelling reason to continue using Windows 95, by all means, continue. You will need OSR 2 for FAT 32 and USB support. DMA support for IDE hard disks is not available. Additionally, it is becoming very difficult to find peripherals and cards that include Windows 95 drivers.

What if I'm using Windows 2000?

Windows 2000 can, in some instances, derive more performance from your M571 system, and it is more stable than DOS-based OSs (Win 95, 98, & ME). On the other hand, Windows 2000 will place additional demands on an M571 for the additional performance it supports. If your system is overclocked or tweaked to the edge of stability, installing Windows 2000 may cause your system to become unstable. For instance, My K6 3 400 system overclocked to 458 MHz (83.3 x 5.5) and running 2.28 core volts on Windows 98 FE required 2.35 core volts to the processor to remain stable. Until the extra voltage was added to the processor, the system would lock up with a blue screen after about 5 minutes of operation.


Another difficulty faced with using Windows 2000 concerns the IDE drivers. The IDE driver provided with Windows 2000 for the SiS 5597/5598 chipset will not allow DMA to be enabled. (DMA is enabled in the Device Manager. Enabling DMA will increase the performance of DMA compatible IDE devices considerably.)


Enabling DMA in Windows 2000 concerns ACPI – Advanced Configuration and Power management Interface. An IDE driver that will interact successfully with the M571 ACPI and allow DMA to be enabled is available from SiS at this link: IDE 2.02 It is a straightforward operation to download the driver from this link and, following the instructions, install the driver.


The M571 has a BIOS limitation of 32 GB hard drives. Manufacturers often provide a software overlay capability to permit the use of larger hard drives on systems limited to 32 GB disks. I have two M571 systems using 80 GB Western Digital hard drives, using their overlay application provided with the disks. (This program is also available for download from the Western Digital site.) Using this overlay enabled DMA with the use of the standard Windows 2000 IDE drivers.

What are your personal performance recommendations?

These are my recommendations for upgrading M571 3.2, 3.2a, or 7.0 based system as of December 2001. Each of these steps assumes that CMOS settings and Windows configurations are optimized. Tips can be found web pages included in the Links section of this site. This costs nothing to do and results in measurable gains in performance. Like anything else, it is up to the reader to determine what upgrades are appropriate to their intended use, but I suggest performing upgrades in this order:


Install a PCI video board. The performance increase is substantial. This was my first step, and with a total of 64 MB of memory and a K6 200 MHz processor, the performance increase was very significant. The on-board M571 video uses system memory, which is very slow and poorly suited for video use (unless you are using the system as a dedicated appliance, in which case the onboard video saves cost and power consumption). Also, the processor is freed from having to perform video calculations. This is mandatory if any graphic intensive gaming or overclocking is to be done with the system. Finally, the on board video drivers do not support as wide a range of applications (especially games) as the drivers of many video boards. Disable the on board VGA in CMOS settings and with JP3.


Install no more and no less than two 64 MB CAS 2 PC100 or PC 133 DIMMs, unless you are using a K6 3 processor. If you are using Windows 2000 or Windows XP and have a K6 3 processor, use a pair of 128 MB CAS 2 DIMMs if you require more than 128 MB to run your applications with these operating systems.


Upgrade the processor as outlined in this section. K6 3 processors are always a good choice: I am using a K6 3 333 MHz processor in one system and it runs great at 400 MHz! My K6 3 400 system is rock steady at 458 MHz.

A K6 3 400 or K6 3 450 is ideal, but they are becoming difficult to find new. I have found the slower 333 version more readily available.

If you cannot find these chips in your area, use a K6 2 500. They are more available and are reasonably priced. No setting on an M571 will overclock this processor, so run it as fast as your board and PCI equipment will allow.

Remember that running Front Side Bus speeds of 75 MHz or 83.3 MHz will overclock the PCI bus, as detailed in the JP5 D jumper discussion on this page. Video, memory, and hard disk performance will be increased, but your components must be able to handle the faster  speed. If you have a slow hard disk, you may need to use a slower PIO CMOS setting for that disk in the setup utility. Finally, memory access is controlled by Front Side Bus speed, so any improvement will usually require PC100 or faster memory and provide increased performance of applications which access memory routinely. This last point is especially important with a K6 2, which has no on board cache.

This installation will be rock solid reliable with a good cooling fan, proper case ventilation, and the 04/21/99 BIOS. Naturally, your choice here will depend on chip availability and the money you are willing to spend.


A fast hard disk really wakes up a system. Research which hard disks perform well. Make sure to get a 7200 rpm unit or better and insist on drives that have a 2 MB buffer. Even though the M571 is limited to 33 MHz ATA data transfers, there is a noticeable increase in performance with a faster disk. If a disk larger than 8.4 GB is used, you must install the 4/21/99 BIOS image. (This also applies to USB capability, by the way!) This BIOS release will support disks up to 32 GB. Do not use SiS IDE drivers! Use the Microsoft drivers provided with Win 95 OSR 2, Win 98, or a later OS. The Microsoft drivers will have a DMA box in the HDD Device Manager entry under settings (Win 9x/ME only), which should be checked. Enabling DMA will give you noticeably faster hard disk access times.

Windows 2000 is another matter; many users are still trying to get DMA working on this operating system. Marcos of Brazil provided me with the tip that SiS has a new driver that will enable DMA on the M571 IDE channels when running Windows 2000. To download these drivers from the SiS site, use this link: http://driver2.sis.com/utility/ide/ide202.zip. This zip file is about 5.6 MB. We are indebted to Marcos for passing on this valuable discovery!

I have found that the Western Digital overlay application that permits drives larger than 32 GB will also enable DMA when used with Windows 2000 standard IDE drivers.


Consider tweaking your chipset settings. Normally, this practice is for those who demand peak performance from their M571 system, as it entails more technical understanding than other upgrade tips on this site. However, for those who understand what is involved, useful gains can be achieved.


Use a PCI sound card and shut off the CMI 8330 on board sound in CMOS and at JP11.


Use a modern operating system. Linux offers many advantages, although its configuration can be difficult, depending on one's level of experience. Also, drivers are not always available for some components. Microsoft's Windows 2000 and Windows XP are much more efficient than their old DOS based predecessors, such as Win95, Win98, and Win ME, and provide support for many applications that you may already have. They are more reliable and offer better performance than DOS based Windows OSs.


I used this site (Cain Nelson, who built it, had it then), Franc Zabkar's site, and help from EYO Tech forum participants when I performed my M571 3.2 upgrade in 1999. This page adds further research and suggestions from folks far wiser in this game than me. None of this information is "secret" anymore; it is a path known by a number of people who successfully sought more performance from a mainboard that was cheap, but offered a surprising level of power for the money.

Remember that although this information is proven, you are the only one that has any control over your results. Use this information only if you are willing to take full responsibility for the craftsmanship it requires and if you are willing to assume all of your own risks. I assume no responsibility of any kind for anyone using this information in any way!


This page was last modified on 19 July 2004