Overclocking guide
By: CrazeD
There is a lot to learn and understand before you begin to overclock. Overclocking can be exciting as long as you know what you're doing... if not, it could be hazardous to your components. Let's get started.
I'm going to focus this guide on AMD Athlon 64-bit chips, simply because I own one and can relate to my experiences a little, however some information found in this guide can be used for any CPU.
1. The hazards...
You need to understand the dangers of overclocking. When you overclock your AMD A64 chip, you are usually upping the FSB (Front Side Bus) speed. However, this does not only up the CPU clock...it increases the frequency of everything that communicates with the FSB. This includes the chipset, your video card, RAM, and your hard drives. Overclocking has caused data corruption before because it has upped the IDE frequency to a level that the hard drive can no longer handle. There have also been instances where an overclock has upped the PCI bus too high (it is very sensitive to adjustment) and that has fried components. Fortunately, most good boards have locked the frequencies to prevent this from happening; and some give you an option.
Heat is another big danger when overclocking. Making the components run faster also makes them hotter. The frequency change alone usually doesn't make a large overall effect on heating, but when you up the core voltage it can affect temperatures a lot. An aftermarket cooler, or water cooling is recommended for big-time overclockers, though getting that extra little bit of juice out of your chip usually doesn't require this; as long as you have good case cooling.
While you usually can't hurt anything with just the frequencies, you can seriously damage your hardware when you change the voltages. Every component in your PC is very very sensitive to voltage adjustment. For instance, most AMD A64 chips come stock right around 1.4 - 1.45V. 1.8V is the sudden-death point for an AMD A64. Be very careful when adjusting voltages, and always increase by the smallest available increments. Only adjust your voltage if all-else fails to stablize your overclock. Never exceed 1.55V for a 24/7 overclock. Never exceed 1.63V even for suicide runs. The chip will run very hot at these voltages, so just keep it around 1.55V to be safe.
2. Understanding how overclocking works...
Everything to do with overclocking is done through your BIOS. Pre-built PC's (eMachines, Dell, Compaq...etc) are not able to overclock through the BIOS. This is because the companies lock that portion of the BIOS so that users cannot screw things up and then return it and get a new one. Sometimes you can overclock with Motherboard Monitor if your motherboard is supported but it has not been updated for a very long time so chances are it's not. Overclocking with a program is never a good idea to start with. You won't get a stable overclock, and it's a PITA to reset if it comes to that. With the BIOS, you simply reset CMOS and it will return to default speeds.
When you overclock, go by small increments. Up the FSB/HTT slowly. I usually go 5MHz at a time. This takes a long time but it is stable.
There are four terms you need to familiarize yourself with. 1. FSB, 2. HTT, 3. Multiplier, 4. Memory divider..
The FSB (actually called the HTT [Hyper-Transport] in an AMD A64 system) is what you increase to up the CPU speed. The HTT (actually it's called the LDT, but in your BIOS you'll probably find it as HTT).
You don't really have to worry about the LDT, as long as it doesn't exceed 1000MHz. Once it exceeds 1000MHz, your system will become unstable and it can corrupt your OS and all kinds of nasty things. As you overclock, you will be increasing the LDT speed as well. What you need to do is set the LDT multiplier to 4, or (depending on your BIOS) manually adjust the LDT to 800MHz. You want to get as close to 1000Mhz as possible without going over.
The multiplier. Basically the multiplier...multiplies...the frequency. For example: If you buy a 2.0Ghz chip, it's going to be running at 200MHz (FSB/HTT) times 10 (multiplier) which is 2000MHz (or, 2.0GHz). On some chips (The FX-** series for example) you can raise the multiplier which can make overclocking a lot faster, because you are just upping the CPU clock and not everything. Though, sadly, most AMD A64 (the single-core and X2 series) you can not raise the multiplier. Though, you can lower it. Why would you want to do that? Well, you can achieve a higher FSB/HTT that way. You can buy DDR500 RAM (runs at 250MHz [more on that in a second]) and make it actually run at 250MHz by dropping the multiplier to 8 and then upping the FSB/HTT to 250. You're still at 2.0GHz, but now your RAM is running 50MHz faster.
Now, you have to understand how the RAM gets its speed; this is important to know. I'll be using DDR400 RAM as an example. DDR stands for Double-Data Rate. This basically means that an underlying frequency is doubled to achieve a higher, effective frequency. DDR400 RAM has a "real" clock of 200MHz, but an "effective" clock of 400MHz. You may now have seen that the stock FSB runs about the same frequency as your DDR400 RAM.
Lastly, you need to know what a memory divider is, it plays a very important role in overclocking. A memory divider is basically a ratio between the FSB/HTT and the memory. At stock speeds, this divider is 1:1. Now, as you raise the FSB/HTT, you are also increasing the memory frequency. You will only get so far before you will no longer be able to POST or you will get errors because the RAM can't operate at such high speeds. There is a way around this...and that is to underclock the RAM. You do this by setting up a memory divider. So, if you have DDR400 RAM (running at 200MHz remember) and you raise the FSB/HTT to 230MHz, then your RAM will be running at 230MHz (460MHz "effective" clock). With most un-tweaked RAM, you probably will have bad results with this, so, we'd need to make the RAM run at DDR333 (166MHz) speeds. With the FSB at 230, the RAM will be running at 196MHz - just about where it started at! So now your RAM is running just about default speeds, but your CPU is now .3GHz higher!
3. Voltages...
I won't lie, changing the voltages are dangerous! You can very quickly and very easily do permenate damage to your CPU (or other components) by raising the voltage too high. As said earlier, these components are extremely sensitive to any adjustment. Now, you will at some point have to raise the vCORE (the CPU voltage) to regain stability. A higher frequency needs a bit more power to run. Always increase the voltage at the smallest available increment, so that you don't over-do it. Just a small amount is usually enough to make it stable again.
If you want to overclock your RAM too, you can also up the voltage to this. Do this even more carefully, as the RAM is very very sensitive. Find what the RAM runs at stock and go maybe .1 or .2V higher, no more or you risk damaging it. Some RAM is different and can handle it, but most can't handle a large difference.
Always remember that increasing the voltage will in-turn increase the heat quite a bit. Make sure you have good cooling.
4. Stability...
Once you get a little overclock going, you need to test its stability. You do this with a program that is designed to stress your CPU (or other components) for a long period of time. Prime95 is such a program. It is free, and works very well.
Run it for about 12 hours straight. If it has 0 errors, 0 warnings then you are rock-solid. Even 1 error and you are not stable, so something must change.
If, after just upping the FSB/HTT, your overclock is not stable, there are a few things to try. 1. Did you set up a memory divider? If not, definitely do that to take memory out of the equation. 2. Is your processor overheating? Heat is a big factor in stability. 3. Are your RAM timings too tight? Loosen them a bit just to ensure that RAM is not part of the problem. 4. If all-else fails, increase the CPU core voltage very slightly. Check your temperatures afterwards. After each step, run Prime95 for 12 hours and see what you get.
If, even after increasing the voltage, you still aren't stable then have just hit a wall with your CPU. There is a point where it simply will not go higher, there's nothing you can do about it.
If you haven't guessed yet, overclocking takes a fair bit of time.
5. Cooling...
The stock AMD A64 coolers are quite nice, and do a very good job keeping the chip cooled - at default speeds, anyway. Once you start overclocking and the temperatures start rising it can only struggle to keep up. If you are serious about overclocking and expect large results, then an aftermarket cooler is for you. The Zalman CNPS9000 is one of the best - priced at 45$ USD. Zalman always has a CNPS7000, which is a little cheaper than the CNPS9000 but not quite as efficient, though it is still a huge increase from the stock cooler. There are tons of air coolers to choose from, do a little research and get what fits your budget.
There's always the option of watercooling. If you are indeed serious about overclocking than this may be right for you. A good watercooling loop will run you around $275 USD minimum, and a good amount of watercooling knowledge to set it all up properly. You shouldn't need watercooling unless you are really into overclocking though. You should be able to get a 30 - 40% OC on air, but it greatly depends on living conditions and how well your case cooling is.
You want to keep your idle temps in the ballpark of low - mid 40's (celcius) and your load temps no more than 55 degrees celcius. 80*C is the absolute inplosion point for AMD A64 chips, however high temps (upper 60's and above) could damage the chip.
6. Software...
There is a few programs that can save you some headache and help you out with overclocking. Below is a list of all the programs I recommend:
CPU-z - Download here - Website - This tool is useful for gathering information about your system. It tells you your FSB/HTT and LDT speeds, mutlipliers, memory frequency and timings - and a bunch more. No temperatures, though.
Super PI Mod - Download here - Website - This program is good for benchmarking your CPU. It calculates huge integers and times how long it takes to do so. The most popular test is the "1M" test. Take a test at default speeds and then one after, see the improvement.
Everest - Download here - Website - This is a VERY handy program that tells you just about every detail in your computer. It shows you all the temperatures, voltages, clocks - EVERYTHING!
Prime95 - Download here - Website - Prime95 is a tool used to test the stability if your CPU, RAM, and power consumption. It runs most of the components at 100% usage, so it also makes the components generate a lot of heat - an easy way to test the load temperatues.
Sandra XI - Download here - Website - Sandra is a cool program that can benchmark just about every component in your PC. But not only can it benchmark them, but you can compare them to four different referances to see how you compare to top-of-the-line hardware.
7. Trouble-shooting...
If you're having some trouble overclocking, the best thing to do (if you're unsure) is to research it a little bit. Find a computer forum and browse around a bit to look for some answers to a similar problem of yours.
The most common problem is a BSOD (Blue Screen of Death) or your PC just freezing up, randomly restarting etc, etc. Usually, it's a memory issue. I frequent a couple computer forums and the number one cause of this stuff is just the memory. Sometimes it's the frequency is too high (so you need to setup a memory divider) or the timings need to be loosened. For your regular-every day DDR400 RAM, 3.0-3-3-8 2T @ 166MHz is a good starting point. Once you get your CPU frequency in a happy place, you can focus on the RAM - but it's nice to have it out of the equation.
Other problems could be power issues. An overclocked component draws more power than it previously did, so make sure your power supply is sufficient.
Make sure you have sufficient cooling as well, as heat can cause problems.
If you're still unsure, try to find someone who has some experiance with overclocking and chat with them.
8. That's it....
That's a wrap for now. Overclocking really isn't that hard and there isn't a terribly large amount of information to cover. This is just the basics, after all. A lot of the knowledge most of us overclockers have came from pure experience and trial-and-error. Just make sure your errors aren't costly ones.
If you have any questions or problems- or feel I left something out, please feel free to contact me and I'll be glad to help you out. eMail: crazed_rider@yahoo.com - AIM: XxCrazeDxFreaKxX - XFire: crazed90 - MSN: silentkillerdelta@yahoo.com
Thanks for reading, I hope you learned something.
Enjoy.
By: CrazeD
There is a lot to learn and understand before you begin to overclock. Overclocking can be exciting as long as you know what you're doing... if not, it could be hazardous to your components. Let's get started.
I'm going to focus this guide on AMD Athlon 64-bit chips, simply because I own one and can relate to my experiences a little, however some information found in this guide can be used for any CPU.
1. The hazards...
You need to understand the dangers of overclocking. When you overclock your AMD A64 chip, you are usually upping the FSB (Front Side Bus) speed. However, this does not only up the CPU clock...it increases the frequency of everything that communicates with the FSB. This includes the chipset, your video card, RAM, and your hard drives. Overclocking has caused data corruption before because it has upped the IDE frequency to a level that the hard drive can no longer handle. There have also been instances where an overclock has upped the PCI bus too high (it is very sensitive to adjustment) and that has fried components. Fortunately, most good boards have locked the frequencies to prevent this from happening; and some give you an option.
Heat is another big danger when overclocking. Making the components run faster also makes them hotter. The frequency change alone usually doesn't make a large overall effect on heating, but when you up the core voltage it can affect temperatures a lot. An aftermarket cooler, or water cooling is recommended for big-time overclockers, though getting that extra little bit of juice out of your chip usually doesn't require this; as long as you have good case cooling.
While you usually can't hurt anything with just the frequencies, you can seriously damage your hardware when you change the voltages. Every component in your PC is very very sensitive to voltage adjustment. For instance, most AMD A64 chips come stock right around 1.4 - 1.45V. 1.8V is the sudden-death point for an AMD A64. Be very careful when adjusting voltages, and always increase by the smallest available increments. Only adjust your voltage if all-else fails to stablize your overclock. Never exceed 1.55V for a 24/7 overclock. Never exceed 1.63V even for suicide runs. The chip will run very hot at these voltages, so just keep it around 1.55V to be safe.
2. Understanding how overclocking works...
Everything to do with overclocking is done through your BIOS. Pre-built PC's (eMachines, Dell, Compaq...etc) are not able to overclock through the BIOS. This is because the companies lock that portion of the BIOS so that users cannot screw things up and then return it and get a new one. Sometimes you can overclock with Motherboard Monitor if your motherboard is supported but it has not been updated for a very long time so chances are it's not. Overclocking with a program is never a good idea to start with. You won't get a stable overclock, and it's a PITA to reset if it comes to that. With the BIOS, you simply reset CMOS and it will return to default speeds.
When you overclock, go by small increments. Up the FSB/HTT slowly. I usually go 5MHz at a time. This takes a long time but it is stable.
There are four terms you need to familiarize yourself with. 1. FSB, 2. HTT, 3. Multiplier, 4. Memory divider..
The FSB (actually called the HTT [Hyper-Transport] in an AMD A64 system) is what you increase to up the CPU speed. The HTT (actually it's called the LDT, but in your BIOS you'll probably find it as HTT).
You don't really have to worry about the LDT, as long as it doesn't exceed 1000MHz. Once it exceeds 1000MHz, your system will become unstable and it can corrupt your OS and all kinds of nasty things. As you overclock, you will be increasing the LDT speed as well. What you need to do is set the LDT multiplier to 4, or (depending on your BIOS) manually adjust the LDT to 800MHz. You want to get as close to 1000Mhz as possible without going over.
The multiplier. Basically the multiplier...multiplies...the frequency. For example: If you buy a 2.0Ghz chip, it's going to be running at 200MHz (FSB/HTT) times 10 (multiplier) which is 2000MHz (or, 2.0GHz). On some chips (The FX-** series for example) you can raise the multiplier which can make overclocking a lot faster, because you are just upping the CPU clock and not everything. Though, sadly, most AMD A64 (the single-core and X2 series) you can not raise the multiplier. Though, you can lower it. Why would you want to do that? Well, you can achieve a higher FSB/HTT that way. You can buy DDR500 RAM (runs at 250MHz [more on that in a second]) and make it actually run at 250MHz by dropping the multiplier to 8 and then upping the FSB/HTT to 250. You're still at 2.0GHz, but now your RAM is running 50MHz faster.
Now, you have to understand how the RAM gets its speed; this is important to know. I'll be using DDR400 RAM as an example. DDR stands for Double-Data Rate. This basically means that an underlying frequency is doubled to achieve a higher, effective frequency. DDR400 RAM has a "real" clock of 200MHz, but an "effective" clock of 400MHz. You may now have seen that the stock FSB runs about the same frequency as your DDR400 RAM.
Lastly, you need to know what a memory divider is, it plays a very important role in overclocking. A memory divider is basically a ratio between the FSB/HTT and the memory. At stock speeds, this divider is 1:1. Now, as you raise the FSB/HTT, you are also increasing the memory frequency. You will only get so far before you will no longer be able to POST or you will get errors because the RAM can't operate at such high speeds. There is a way around this...and that is to underclock the RAM. You do this by setting up a memory divider. So, if you have DDR400 RAM (running at 200MHz remember) and you raise the FSB/HTT to 230MHz, then your RAM will be running at 230MHz (460MHz "effective" clock). With most un-tweaked RAM, you probably will have bad results with this, so, we'd need to make the RAM run at DDR333 (166MHz) speeds. With the FSB at 230, the RAM will be running at 196MHz - just about where it started at! So now your RAM is running just about default speeds, but your CPU is now .3GHz higher!
3. Voltages...
I won't lie, changing the voltages are dangerous! You can very quickly and very easily do permenate damage to your CPU (or other components) by raising the voltage too high. As said earlier, these components are extremely sensitive to any adjustment. Now, you will at some point have to raise the vCORE (the CPU voltage) to regain stability. A higher frequency needs a bit more power to run. Always increase the voltage at the smallest available increment, so that you don't over-do it. Just a small amount is usually enough to make it stable again.
If you want to overclock your RAM too, you can also up the voltage to this. Do this even more carefully, as the RAM is very very sensitive. Find what the RAM runs at stock and go maybe .1 or .2V higher, no more or you risk damaging it. Some RAM is different and can handle it, but most can't handle a large difference.
Always remember that increasing the voltage will in-turn increase the heat quite a bit. Make sure you have good cooling.
4. Stability...
Once you get a little overclock going, you need to test its stability. You do this with a program that is designed to stress your CPU (or other components) for a long period of time. Prime95 is such a program. It is free, and works very well.
Run it for about 12 hours straight. If it has 0 errors, 0 warnings then you are rock-solid. Even 1 error and you are not stable, so something must change.
If, after just upping the FSB/HTT, your overclock is not stable, there are a few things to try. 1. Did you set up a memory divider? If not, definitely do that to take memory out of the equation. 2. Is your processor overheating? Heat is a big factor in stability. 3. Are your RAM timings too tight? Loosen them a bit just to ensure that RAM is not part of the problem. 4. If all-else fails, increase the CPU core voltage very slightly. Check your temperatures afterwards. After each step, run Prime95 for 12 hours and see what you get.
If, even after increasing the voltage, you still aren't stable then have just hit a wall with your CPU. There is a point where it simply will not go higher, there's nothing you can do about it.
If you haven't guessed yet, overclocking takes a fair bit of time.
5. Cooling...
The stock AMD A64 coolers are quite nice, and do a very good job keeping the chip cooled - at default speeds, anyway. Once you start overclocking and the temperatures start rising it can only struggle to keep up. If you are serious about overclocking and expect large results, then an aftermarket cooler is for you. The Zalman CNPS9000 is one of the best - priced at 45$ USD. Zalman always has a CNPS7000, which is a little cheaper than the CNPS9000 but not quite as efficient, though it is still a huge increase from the stock cooler. There are tons of air coolers to choose from, do a little research and get what fits your budget.
There's always the option of watercooling. If you are indeed serious about overclocking than this may be right for you. A good watercooling loop will run you around $275 USD minimum, and a good amount of watercooling knowledge to set it all up properly. You shouldn't need watercooling unless you are really into overclocking though. You should be able to get a 30 - 40% OC on air, but it greatly depends on living conditions and how well your case cooling is.
You want to keep your idle temps in the ballpark of low - mid 40's (celcius) and your load temps no more than 55 degrees celcius. 80*C is the absolute inplosion point for AMD A64 chips, however high temps (upper 60's and above) could damage the chip.
6. Software...
There is a few programs that can save you some headache and help you out with overclocking. Below is a list of all the programs I recommend:
CPU-z - Download here - Website - This tool is useful for gathering information about your system. It tells you your FSB/HTT and LDT speeds, mutlipliers, memory frequency and timings - and a bunch more. No temperatures, though.
Super PI Mod - Download here - Website - This program is good for benchmarking your CPU. It calculates huge integers and times how long it takes to do so. The most popular test is the "1M" test. Take a test at default speeds and then one after, see the improvement.
Everest - Download here - Website - This is a VERY handy program that tells you just about every detail in your computer. It shows you all the temperatures, voltages, clocks - EVERYTHING!
Prime95 - Download here - Website - Prime95 is a tool used to test the stability if your CPU, RAM, and power consumption. It runs most of the components at 100% usage, so it also makes the components generate a lot of heat - an easy way to test the load temperatues.
Sandra XI - Download here - Website - Sandra is a cool program that can benchmark just about every component in your PC. But not only can it benchmark them, but you can compare them to four different referances to see how you compare to top-of-the-line hardware.
7. Trouble-shooting...
If you're having some trouble overclocking, the best thing to do (if you're unsure) is to research it a little bit. Find a computer forum and browse around a bit to look for some answers to a similar problem of yours.
The most common problem is a BSOD (Blue Screen of Death) or your PC just freezing up, randomly restarting etc, etc. Usually, it's a memory issue. I frequent a couple computer forums and the number one cause of this stuff is just the memory. Sometimes it's the frequency is too high (so you need to setup a memory divider) or the timings need to be loosened. For your regular-every day DDR400 RAM, 3.0-3-3-8 2T @ 166MHz is a good starting point. Once you get your CPU frequency in a happy place, you can focus on the RAM - but it's nice to have it out of the equation.
Other problems could be power issues. An overclocked component draws more power than it previously did, so make sure your power supply is sufficient.
Make sure you have sufficient cooling as well, as heat can cause problems.
If you're still unsure, try to find someone who has some experiance with overclocking and chat with them.
8. That's it....
That's a wrap for now. Overclocking really isn't that hard and there isn't a terribly large amount of information to cover. This is just the basics, after all. A lot of the knowledge most of us overclockers have came from pure experience and trial-and-error. Just make sure your errors aren't costly ones.
If you have any questions or problems- or feel I left something out, please feel free to contact me and I'll be glad to help you out. eMail: crazed_rider@yahoo.com - AIM: XxCrazeDxFreaKxX - XFire: crazed90 - MSN: silentkillerdelta@yahoo.com
Thanks for reading, I hope you learned something.
Enjoy.
Last edited by CrazeD (2007-01-08 04:29:49)