My First Overclock Attempt: AMD Duron 850MHz Spitfire

Overclocking. If this term sounds alien, allow me to share my knowledge about it. This is based on research, gathered knowledge and personal interpretation. So here it goes:


Overclocking, what is it? Overclocking is the process of getting your hardware to run faster than what was specified and tested by the manufacturer. The simplest way to describe it is pushing your hardware to it most stable limits. Overclocking is not limited to the CPU but also extends to your GPU, your RAM as well your Motherboard Chipsets (Northbridge Chipset and Southbridge Chipset, I'm not too familiar with this yet, but I do know it's possible.) But for this article, I only attempted to Overclock the CPU because my current test system has no GPU and pitiful RAM.


Now I hear the "purists" screaming "Why!? Why would you do that!?". Well, to put it simply, overclocking is done to get the most out of your current hardware (while maintaining stability of course.) with little to no cost, the little cost would probably come in the form of cooling hardware since heat will play a factor in your overclocking, more on this later on.


At this moment, I assume I'll be hearing something like "Okay, great. That's all good stuff. But what's the catch?" Well, as with anything in life, there is always some degree of risk involved. I'll list down some of the most common risks (as well as possible solutions to mitigate some of the risks) involved when one decides to overclock:

1. Overheating. When you are overclocking, temperature will always be a factor. Increased speed = increased temperature of hardware being overclocked. This can be decreased by installation of a proper system cooling.
2. Increased probability of system crashes and failures. Take note, I said probability, not certainty. This probability can be decreased (if not removed) by proper benchmarking and testing to get the most stable overclock possible.
3. Voiding your warranty. Unless it's stipulated in your warranty or specified by the manufacturer, damage caused by overclocking is generally not covered by warranty.
4. Decreased Hardware lifespan. Doubling the usual wear and tear will double the speed of deterioration (the same with most objects used in life).

These are the top risks in my opinion.

Now, with the presence of risks, there is also the presence of benefits which I will list below:

1. Increase in system performance.
2. Money saved from buying higher performance hardware.
3. Increased understanding and appreciation for your system, hardware, generally increased knowledge. (This is priceless in my opinion.)
4. Bragging rights. :] (if successful of course!)

These are the top benefits in my opinion.

Now let's get into the meat of this article. The actual overclock, as mentioned above, was only done directly to affect the CPU.

Here is a short overview of the system I tested this on:

(The Spitfire Test System, Photo by Thomas Joseph Huang)

PC Age (approximately 10 years old, hasn't been used in 5 years)

CPU: AMD Duron 850MHz (Codename: Spitfire)

Motherboard: Biostar M7VKG

RAM: 128MB PC-133 MS3828UPP SDRAM 100MHz

Graphics: Onboard (Microsoft S3 Graphics ProSavage 8A26)

PSU: Frontier 235w

Cooling System: No case fans,1 PSU exhaust fan

Case: Closed case with very minimal airflow vents

OS: Windows XP

(No overclock statistics, Photo by Thomas Joseph Huang)

Now that you know what I'm working with, here is the initial no overclock statistics of what my CPU is currently running at (see image, my apologies for the quality, there was interference with my iPhone's camera and the monitor). I was able to check these statistics using the freeware called CPUID CPU-Z. It's commonly used for viewing the current hardware statistics of your machine. As you can see, the core speed is steady at 850MHz. You only need to focus on the lower left section labeled "Clocks (Core #0)

Now upon restarting, I entered the BIOS menu by hitting the Delete button, I looked around to see what I could tinker with and found that this Motherboard is not too Overclocker friendly, I only found 2 customizable areas (the other one will be mentioned near the end of this article), the first one I found was under this sequence: Frequency/Voltage Control -> Linear CPU Clock Function (the default value is Disabled) -> Enabled function. Enabling this function now allows you to make modifications to the CPU Clock which has a range from 100MHz-132MHz. I've decided to try my adjustments in increments of 5MHz as it is recommended to gradually test. The CPU Multiplier is locked at 8.5 (This is a CPU limitation as well as a Motherboard limitation in this case) however I did a little research (see reference below) and I read that the CPU can be unlocked by making a physical adjustment to the L1 Golden Bridges on the surface of CPU itself which would unlock the CPU Multiplier allowing you to make adjustments here as well (I'm not comfortable enough to try this one out yet, but when I decide to do so, I will write about it, don't worry.). Another side note, apparently, adjusting the CPU Clock function directly increases the Front Side Bus (FSB) speed. The value that you set under the CPU Clock Function is the same as the value for the FSB speed, this will give you an increase in your overall Core Speed. (example: Setting the CPU Clock function value to 105MHz = 105MHz FSB Speed). Getting your Core Speed using this method is done through this simple formula (FSB x CPU Multiplier = CPU Speed/Core Speed, the example for my stock CPU: 100 x 8.5 = 850MHz)

The setting of this value apparently affects the DRAM Timing of your RAM as well, it also takes the same value set for your CPU Clock function.

For the benefit of transferring knowledge:

"Front Side Bus (FSB) - The Front Side Bus is the most important bus to consider when you are talking about the performance of a computer. The FSB connects the processor (CPU) in your computer to the system memory. The faster the FSB is, the faster you can get data to your processor. The faster you get data to the processor, the faster your processor can do work on it. The speed of the front side bus depends on the processor and motherboard chipset you are using as well as the system clock." (Source Website: http://www.directron.com/fsbguide.html)

Reference for Duron CPU Multiplier Unlocking: (http://www.xbitlabs.com/articles/cpu/display/duron-600.html)

For the purpose of this article when I say I adjust the FSB, I am referring to the CPU Clock Function in the BIOS that has a directly proportionate change to the FSB.

(Test 1 @ 105MHz FSB, Photo by Thomas Joseph Huang)

For my first overclocking run, I set the FSB to 105MHz and this resulted in a Core Speed of 892.7MHz, the system successfully booted to Windows. I performed simple benchmarking (opened multiple programs simultaneously, left running for 15 minutes, it's a short time, I know.) The CPU Temperature went up to 48 degrees Celsius from it's original 47 degrees Celsius. (See Test 1 image)

(Test 2 @110MHz FSB, Photo by Thomas Joseph Huang)

Now for the second run, I set the FSB to 110MHz and this resulted in a Core Speed of 935.5MHz, the system also successfully booted to Windows. I performed the same simple benchmarking as the previous test. Upon checking, the CPU Temperature went up to 50 degrees Celsius. (See Test 2 image)

(Test 3, Threshold Reached, Photo by Thomas Joseph Huang)

And for the next run, I set the FSB to 115MHz and this resulted in the computer freezing at the initial boot screen after the settings in the BIOS were saved. But based on the initial screen, the potential Core Speed would have been 978MHz. Upon resetting the machine, this resulted in a BSOD forcing me to pull the plug in order to reset the BIOS back to normal. This is the current threshold of my PC. (See Test 3 image)

And this is where my attempt has temporarily ended. However, I do not consider Tests 1 and 2 successful Overclocks because I need to run a complete benchmark and stress test on this to make sure that the system runs and stays stable. After that is when I can determine the success of my Overclock. I suppose you could call them partially successful Overclocks.


Just an additional side note, I also found that you can also adjust your DRAM frequency using these steps in the BIOS for this Motherboard: Advanced Chipset Features -> DRAM CLK, here you have 2 options: Host CLK and HCLK+33m, the second option means your Host Clock plus 33MHz, in this case the Host CLK is at 100MHz which means there can be an additional 33MHz boost for your RAM. 

This attempt experience was a good learning opportunity for me to get know the inner workings of a PC as well as tinker with technology which is something that I enjoy. I now have a side project apart from building my rig: overhauling this system and rebuilding it into something  and pushing its limits again. >:)


*apologies for the photo quality, there was some interference between the monitor and my iPhone camera.

I will gather some benchmarking tools and run more tests on the current system, stay tuned for that article!