*NOTE* This has originated from www.extremeoverclocking.com and their forums. I take no credit in the making of this guide as I am not the aurthor. I am simply reposting this for others to view.
Introducing the New & Improved AMD Overclocking Guide which will take a look at not only the principles of overclocking an Athlon based system, but also this particular processor and the new obstacles that stand in the way of the perfect overclocking system.
Basic Terms of Overclocking
Chipset - A chipset is defined as “a group of microchips designed to work as a unit in performing one or more related functions.” As a general rule, today’s chipsets consist of two parts, a Northbridge and a Southbridge. Both of these terms will be discussed later, but the two working in tandem creates a better and more efficient flow of data with fewer conflicts. Common chipsets used with the Athlon XP processor at the time include the VIA KT400 as well as the nVidia nForce2. The nForce2 has emerged as a great chipset is the choice of overclockers.
Clock Multiplier - The Clock Multiplier is an internal setting of the processor that is used to determine the processor speed. As an example, if you have a processor that is set at the factory with a clock multiplier of 10 have a FSB of 100MHz, then the resulting processor speed is 1000MHz or 1GHz. It's a very simple and easy term but used frequently.
Double Data Rate (DDR) - Double Data Rate, or DDR as it is commonly called, is becoming very popular with the computer industry lately. DDR allows for the support of data transfers on both edges of each clock cycle (the rising and falling edges), effectively doubling the memory chip's data throughput. And even better is that all of the motherboards and the Athlon processors themselves support this feature. So not only can we double the effectiveness of our memory, but we can also double the speed at which data flows between areas of the motherboard too.
Front Side Bus (FSB) - In simple terms, the Front Side Bus (FSB) is the data path between the processor and the main memory. When used from an overclocker’s standpoint it is generally referred to as a speed measured in Megahertz (MHz). The higher the number, the faster the data flows.
Northbridge - The Northbridge is the portion of the chipset that communicates with the computer processor and controls interaction with memory, the Peripheral Component Interconnect (PCI) bus, Level 2 cache, and all Accelerated Graphics Port (AGP) activities. The Northbridge communicates with the processor using the Front Side Bus (FSB).
VAGP - VAGP refers to the voltage setting of the AGP port on the motherboard. Not all motherboards allow for the adjustment of this setting, but for those that do allow for it, the benefits can be great.
VCore - This is the voltage setting for the processor. This is where you can force your speeds to the next level, or completely fry your precious CPU.
VDIMM - This is where you set the voltage levels of your memory. Though higher voltages can help you achieve better overall speeds, they can also cause some system instabilities.
Basics of Overclocking
Now to the basics of overclocking and how it is done. You'll first boot up your computer and enter your BIOS. If your not sure how to do this go into the appropriate motherboard section and search there, it's usually the F2 button or something to that affect.
Once your into the BIOS you can now set your frequencies, voltages and timings. If you have bought a desktop chip and it is post-week 39 you will not be able to change the multiplier. If your not sure check out the steppings FAQ here: http://forums.extremeoverclocking.co...d.php?t=125129
But we must move onward, once you enter the screen in which you see the FSB, Multi, Voltages and Timings you'll know your at the right place. You'll want to start out with a low multiplier (such as 9 or 10) first to find your maximum FSB. First set your multi and then your FSB in 3-5mhz increments and then booting and testing your overclock stability by Prime95 and Memtest (see bottom for list of programs to download). Once you have hit a wall (computer freezes or testing shows your unstable) go back and raise the vcore to your CPU. Once you have found the absolute maximum FSB you can go back and start upping the multiplier in .5 increments. Same idea applies, once you fail, freeze or can't boot raise the vcore until you can. The maximum voltage you want to be running if you have aircooling is 1.95V (in Windows) and 2V with watercooling. If you have the balls you can venture to the about 2.1V for benchmarking but anything more than that will have a high risk of frying your CPU. Adding voltage to the northbridge and VAGP can also help in creating stability for your overclock. Also, a common overlook is the locking of the AGP/PCI frequnecy @ 66mhz. If you don't have a board that allows this it will hold back your overclock.
Now on to the question of RAM and your overclock. This is a key aspect as well and make or break a good overclock. Start out with getting some PC3200 RAM at the least with some decent timings, which are critical for AMD systems. When you first start out with your overclock set the vdimm to 2.8V and loosen the timings to 3-4-4-11 to make sure your RAM isn't hindering your overclock. Once you have found the highest FSB go back and start lowering your timings, as tighter timings result in faster speeds. The best possible timings are 2-2-2-5 but don't be worried if you can't achieve these. For some reason, the nForce2 chipset likes the final number in the RAM timings to be 11 instead of 7-10. If you hit a wall with your RAM, you can increase the voltage to 2.9V, which is the max most mobo's out have unless you plan on doing some voltage mods.
L12 Mod
This has been a hot topic for a while in the overclocking world and I will briefly try to explain it. Since the default fsb of the mobiles is 266, the 266->333/400, L12 mod WILL improve the max fsb on all boards with the nForce2 Ultra 400 chipset (Albatron KX18D Pro, DFI Ultra Infinity, Epox 8RDA, NF7 v2.0, Soltek SL-75FNR2-L, etc.) and possibly others. The most plausible explanation I have heard why this works is because connecting these bridges changes the latency timings between the front side bus and the cpu.
Suggested method:
http://www.geocities.com/trats102002/nf7sFsbsense.html
Alternate method:
http://www.xtremesystems.org/forums...&threadid=15300
Cooling and You
Cooling is a critical aspect of overclocking. As we increase the voltage, this generates more heat and heat creates instability in an overclock, and that is not what we want. Here is a list of general cooling solutions and what beats what: Air Cooling<Water Cooling<Phase Change<LN2. The general cooling overclockers use is air cooling, though some use water and phase change. If you want to have a high overclock you'll want to make sure you have good aircooling at the minimum as an overclocked CPU puts out alot of heat. A great setup would be a Thermalright SP97 with a 92MM Tornado.
Recommended Programs
Prime95
Memtest
SiSoft Sandra 2004
CPU-Z
Motherboard Monitor 5