Fierce Deity
02-Jan-2004, 02:14 AM
first off this is for AMD's, not intel there isn't THAT big of a difference but it could mean you frying the ---- out of your intel if you try this on it. Secondly i take no responsiblitity if you screw up your sytem doing this.. ;)
First you must have some basics on how a motherboard works . It has a clock generator that gives a certain frequency . This value is multiplied by certain numbers , and gives the FSB frequency , RAM bus frequency , PCI frequency , AGP frequency ... Notice that the FSB is not the same thing as RAM bus frequency , this is a common mistake . Also , the RAM and FSB frequencies are different from the actual speed , wich is twice as fast , because they are working at double data rate (DDR) . Example : 266FSB runs at 133mhz . In conclusion , all the speeds on the mobo depend on it's clock generator .
Now , the CPU has 3 important characteristics : it's FSB , multiplier and core voltage . The actual speed of the CPU is FSB freq times multiplier . Example : XP1600+ has a 10.5 multiplier and 133 bus , so it runs at 133 x 10.5 = 1400mhz .
For a good overclock , you will need a good motherboard , wich has settings for fsb increase mhz by mhz , CPU multiplier , CPU core voltage , RAM voltage and RAM latencies .
Most of the AMD chips come multiplier-locked , so you have to unlock them . There are many guides on the unlocking stuff out there , just search one for your particular type of CPU .
First , you must make sure that the CPU is set at the same bus as the RAM , otherwise one of the 2 will not use the other's extra bandwidth , and you don't want that . For example , if you have PC2700 memory and a 166mhz RAM capable motherboard (like the ones with the KT333 chipset) , you should set the CPU also to 166 mhz FSB , and lowering the multiplier below the default value , until the CPU frequency is around 20% under the default one . This is very important .
Now you start increasing the FSB (really you are increasing the mobo's clock , wich takes all the frequencies -AGP,PCI,RAM- higher) , keeping the same low multiplier . The purpose is to get the best FSB stable , no matter what speed the CPU is .To gain stability at high speeds , you must add more voltage to the CPU and to the RAM , sometimes even to the AGP slot , but usually you don't need that . This is a very tricky thing , because voltage brings stability , but also heat , and heat is bad for stability . With a good cooling setup you can take out all the extra heat , try to keep you CPU under 50 C if you can , and never let it go over 60C .
For good performance you can use the best timings on the memory :
CAS latency 2
4-way bank interleave
1T command
RAS & RAS to CAS delay & all the other stuff to minimal latency .
Using these settings help your performance at a certain speed , but they can bring instability , so it's a matter of trial and error . Without them , you'll be able to hit higher frequencies on the RAM , but the real performance may be lower (depends on the type of RAM).
When you hit the highest FSB stable , you can start tweaking on the CPU multiplier . Increase it in 0.5 increments , until you have the highest possible speed , stable . The CPU core voltage increase will help you again .
Remember , always an eye on the temps , 60C is the maximum you should go . The lower the temperature , the more stable at high speeds the CPU is .
First you must have some basics on how a motherboard works . It has a clock generator that gives a certain frequency . This value is multiplied by certain numbers , and gives the FSB frequency , RAM bus frequency , PCI frequency , AGP frequency ... Notice that the FSB is not the same thing as RAM bus frequency , this is a common mistake . Also , the RAM and FSB frequencies are different from the actual speed , wich is twice as fast , because they are working at double data rate (DDR) . Example : 266FSB runs at 133mhz . In conclusion , all the speeds on the mobo depend on it's clock generator .
Now , the CPU has 3 important characteristics : it's FSB , multiplier and core voltage . The actual speed of the CPU is FSB freq times multiplier . Example : XP1600+ has a 10.5 multiplier and 133 bus , so it runs at 133 x 10.5 = 1400mhz .
For a good overclock , you will need a good motherboard , wich has settings for fsb increase mhz by mhz , CPU multiplier , CPU core voltage , RAM voltage and RAM latencies .
Most of the AMD chips come multiplier-locked , so you have to unlock them . There are many guides on the unlocking stuff out there , just search one for your particular type of CPU .
First , you must make sure that the CPU is set at the same bus as the RAM , otherwise one of the 2 will not use the other's extra bandwidth , and you don't want that . For example , if you have PC2700 memory and a 166mhz RAM capable motherboard (like the ones with the KT333 chipset) , you should set the CPU also to 166 mhz FSB , and lowering the multiplier below the default value , until the CPU frequency is around 20% under the default one . This is very important .
Now you start increasing the FSB (really you are increasing the mobo's clock , wich takes all the frequencies -AGP,PCI,RAM- higher) , keeping the same low multiplier . The purpose is to get the best FSB stable , no matter what speed the CPU is .To gain stability at high speeds , you must add more voltage to the CPU and to the RAM , sometimes even to the AGP slot , but usually you don't need that . This is a very tricky thing , because voltage brings stability , but also heat , and heat is bad for stability . With a good cooling setup you can take out all the extra heat , try to keep you CPU under 50 C if you can , and never let it go over 60C .
For good performance you can use the best timings on the memory :
CAS latency 2
4-way bank interleave
1T command
RAS & RAS to CAS delay & all the other stuff to minimal latency .
Using these settings help your performance at a certain speed , but they can bring instability , so it's a matter of trial and error . Without them , you'll be able to hit higher frequencies on the RAM , but the real performance may be lower (depends on the type of RAM).
When you hit the highest FSB stable , you can start tweaking on the CPU multiplier . Increase it in 0.5 increments , until you have the highest possible speed , stable . The CPU core voltage increase will help you again .
Remember , always an eye on the temps , 60C is the maximum you should go . The lower the temperature , the more stable at high speeds the CPU is .