Author Topic: .::Newbie Overclocking Guide::.  (Read 2597 times)

Offline karloco

  • Newbie
  • *
  • Posts: 0
.::Newbie Overclocking Guide::.
« on: March 26, 2003, 04:08:32 PM »
good read:


Your objective is to find the highest stable CPU speed. So for:

INTEL CPUs: Increase the front side bus (FSB) speed a little at a time, then test for stability. Intel's CPU multiplier can not be changed, so increasing bus speed is the only way to overclock. Repeat until it becomes unstable.

AMD CPUs: Increase the front side bus (FSB) speed a little at a time. Note that you may have to decrease the multiplier if the CPU becomes unstable. Test for stability. Repeat until it becomes unstable.

For best performance, you want to find the highest FSB and CPU speed that will run your system without any problems.

If the computer won't boot, crashes, freezes up, pops up error messages or gives you the dreaded Blue Screen Of Death (BSOD), then it's unstable. Raise the voltage one notch at a time until it becomes stable again (check CPU load temps each time). For safety's sake, don't raise the CPU core voltage more than 10% to 15% above default.

CPU temperature at load should be 50c and not higher. It's OK if they get to around 55c as long as the computer is stable. Some people prefer to keep the temperature in the 40s.

Good heatsinks are made by Thermalright, Swiftech, and Alpha.

Thermalright SLK800 ; Swiftech MCX462 ; Alpha 8045 ; Thermalright SK-7.

They do not come with a fan. The lower the CFM of the fan the lower you will be able to overclock because it will increase the heat of your CPU. You need to decide if you want a dead quiet system (around 20cfm fan), a pretty quiet system (around 30cfm fan), a somewhat noticeable noise system (around 40cfm fan), a noisy but not annoying system (around 50cfm fan), or a crazy annoying noise (68cfm or above.)

If you want to hear some fans, go to

See and for good deals.

Use Arctic Alumina thermal grease. Applying a thin layer to the heatsink where it's going to be touching the CPU core. Then use plastic knife to apply a very thin layer onto the CPU core. Rub whatever is left on the heatsink with a finger inside cellophane. Do not apply a thick coat of thermal grease.

The CPU clock speed = CPU Front Side Bus speed (FSB) X CPU multiplier.

The 1400MHz Athlon XP is 133 FSB x 10.5 multiplier =1400MHz.

Increasing the multiplier only affects CPU and RAM.

IMPORTANT: Increasing the FSB changes the speed of the whole motherboard and everything connected to it unless the mobo has a PCI lock.

If your mobo doesn't have a PCI lock that means that too high of an FSB may take your hard drive and PCI cards too far out of specs. So by raising the FSB you will be affecting every component in your system. You want to be careful about the hard drive going above 39mhz because it can get corrupted if you do. The default speed of your hard drive, and every other PCI card is 33 MHz. Mobos usually have a 1/4 PCI divisor to determine how fast the PCI slots are running. On a stock value of 133MHz FSB, you just divide it by 4 to get 33mhz.

For example if you are running the FSB at 150MHz, the 1/4 divisor than you divide 150 by 4 to get the PCI cards at 37.5mhz which should be OK for most devices.

Multiplier can be locked or unlocked. Athlon XP Palomino CPUs are locked, Athlon XP Thoroughbred CPUs are not locked and can be easily changed.

Some mobos also have a 1/5 PCI divisor which kicks in at 166MHz. This means that you can run at 166MHz FSB and still have the PCI cards at 33MHz (166/5).

Higher FSB gives you better all around performance because RAM is working faster.

Think of the FSB as a hose of varying diameter. Think of the CPU as a firemen with buckets waiting to put out a fire. Think of the water as the data need to put out that fire. The fatter the hose, the sooner they get the water. How many men you have waiting with buckets could be thought of in terms of multiplier, sort of. Essentially, your processor can outwork everything else in your system, and frequently waits for data to crunch. With a higher FSB, it gets the data sooner (and can send it sooner, too) so overall system performance increases.

For example, it's better to have an increase of 7 FSB even if the resulting MHz decreased by 20 MHz.

However, if you raise your vcore voltage (most often in .25 increments to about 1.85v), you will be able to get a lot more of an overclock. It increases the heat on your CPU where as raising the FSB does not. That is why it is vital to get a good heatsink/fan.

The default RAM vdimm is around 2.5v (try not to raise it over 2.8v or not at all.)


Athlon XP 1600+ which runs at 1400MHz:

Drop the multiplier if you can to 9.5 and then set the FSB to 170MHz.

Then test the stability of the overclocked system:

Use Prime95 for CPU and RAM stability tests (Prime95 Options ] Torture Test)

This program puts your CPU at max load for long as it is running. If it gives you an error, then the system is unstable.

Keep increasing FSB (usually in 5MHZ increments) and using Prime95 to test the system. After doing this for a while, you may start to run Prime95 for longer periods of time. Sometimes it will only give errors after running for a few hours.

Motherboard Monitor program can be used to watch your temperatures:

PC2100 RAM generally gets to around 150MHz. PC2700 generally does 180MHz.

PC3000 generally does 200MHz. PC3200 generally does 210MHz.

Having your memory at a faster settings may give you a higher overall performance even if you have to decrease CPU clock by 50MHz.

PC2100 settings

T(RAS) 6

T(RCD) 3

T(RP) 3

CAS 2.5

CAS Latency is most important for memory bandwidth. Set it to 2 whenever possible.

2nd important is (Trcd). It is the number of cycles between the row and column access. 2 is good, but 3 is OK.

(Trp) is the precharge time after an active access. 2 is good, but 3 is OK.

Active to Precharge Delay (Tras) is the minimum time for an active access (to perform a single row and column access).

It is the least importance for memory performance. Smaller the better. Usually 5 or 6 or 7 is fine. Tras ]= Trcd + CAS

Sometimes there's also Cmd Rate. 1T is better than 2T

Quality heatsink and fan and high rated RAM are essential for overclocking but so are power supply voltages. If line voltages go 5% lower then rated lines, this may be a sign that you need a better PSU.

Also if you ever wonder why not to spend more money on a better heatsink&fan instead of case fans: The reason is because to have a truly effective cooling system you need to add BOTH a better heatsink AND better case cooling. If you just get a better heatsink and no extra case fans you case will just get hotter and hotter until even with your good heatsink your CPU is still overheating.

SiSoftware Sandra

3dMark with all the tests including DirectX testing features for Direct Draw and Direct3D

The point at which your machine freezes is a good indicator of what may be wrong. If it tosses up the initial part of the bootup screen, then freezes, it's very likely the memory. Slow down the settings and see if that helps. If it freezes later on in the process, it may be the CPU.

Do you ALWAYS have to 'load optimal settings' after updating BIOS (which resets your specific previous settings)? Some say no. However some say that it's good to even always clear the cmos after bios flash before the first boot/post. They say in newer bios there may be some new variables which will get their values from places which weren't used before or were used for other variables...

Offline kcire

  • Semi-Newbie
  • *
  • Posts: 5
.::Newbie Overclocking Guide::.
« Reply #1 on: March 27, 2003, 02:01:22 PM »

Offline kcire

  • Semi-Newbie
  • *
  • Posts: 5
.::Newbie Overclocking Guide::.
« Reply #2 on: March 27, 2003, 02:04:22 PM »

Offline dean

  • Administrator
  • Member
  • *
  • Posts: 3793
Re: .::Newbie Overclocking Guide::.
« Reply #3 on: July 10, 2013, 12:51:59 AM »
w00t! TFS :)
Make yourself heard
Portable Strobist Kit for Rent!
Includes: 2in1 shoot thru/reflective umbrella, lightstand, RF trigger/receiver, 8pcs AA sanyo eneloop, nissin di622, gel filters

Offline ris

  • Member
  • **
  • Posts: 4097
Re: .::Newbie Overclocking Guide::.
« Reply #4 on: July 10, 2013, 03:55:54 AM »
amp!  strike 2
To steal ideas from one person is plagiarism
To steal from many is research