leezard Posted May 30, 2003 Posted May 30, 2003 Copied from high performance pc's website Q: What is overclocking? A: Overclocking is simply running hardware (such as a CPU or Video Card) at a clock speed higher than what it is rated for. Sounds simple but there is much to learn and there are many many good sites that can explain this better than I can. You need to learn as much as you can before going any further. Overclocking can damage your CPU or other system components if you don’t know what your doing! If you want to do this successfully, then you need to put a little time and effort into it. Q: Will overclocking damage my CPU? A: If proper steps are taken to cool your CPU, then overclocking will not damage your CPU. It may in some cases shorten the lifespan depending upon the amount of heat your CPU is subjected to. You can fully expect your CPU will be obsolete by the time it burns out!! Q: I have a ‘name brand’ (Dell, Compaq, Gateway, etc..) computer, can I overclock it? A: In most cases, No. You’ll have to see if there are jumpers on the motherboard or settings in the BIOS to change the CPU bus frequency and/or the multiplier if your CPU will allow it. What you need to do is get into the guts of the computer and see if you can find a model number on the motherboard. Sometimes there will be a sticker on the end expansion slot (ISA or PCI) or it may be printed on the motherboard. IF you can find some numbers on the board, just put them into a search engine and see if it will give you a link to the manufacturers website. Once you know who makes the board you should be able to obtain a manual for the specific board and see if there are any options for changing the CPU speed. This is the only chance you have of being able to know if your board will allow you to overclock. You can possibly trick your CPU/Motherboard into overclocking. Post all your system specs on the newsgroup and we may be able to give you an idea of what to try. You must know what type of CPU and Motherboard you have! Do not just post a computer model (Dell Optiplex) and expect someone to help you, find out all the system specs first. Q: Can I overclock a Laptop? A: There may be some minor instances when you can, but generally NO! Overclocking creates more heat than what the stock setup is designed for and there is no way for the extra heat to escape. Even if you could get it to run stable, the extra heat would turn the laptop into a hot plate. Personally, I would not attempt this!! Q: Can I change the Multiplier on my CPU? A: All of the Intel CPU’s for the last few years (from 233Mhz and up) have been ‘Multiplier Locked’. This means you cannot change the multiplier no matter what you do, no way, no how, forget it! Some CPU's will actually use a lower multiplier if you try to increase it. You will have to adjust the FSB (Front Side Bus frequency) in order to overclock. There are a few CPU's that were manufactured before Intel started the locking process, and occasionally an engineering sample slips out without a locked multiplier, but the chances of getting one are very slim. You can try it, but don't expect it to work. There are some of the older Intel CPUs that were 'Multiplier Limited', meaning you could use a lower multiplier but not higher. I have had 2 P133s that were multiplier limited. AMD is now starting to do the same, but there are some CPU’s or motherboards that can be worked on to change the multiplier, and some CPUs that are unlocked. There are many reviews out there about this. See some of the sites listed on the links page. Most all K6 CPUs will allow you to change the multiplier. Q: My system is just not stable (crashes or locks up) when I overclock my CPU! A: There are many factors that can cause this: * The biggest factor is needing to increase the CPU Core Voltage. In General, you can safely increase the core voltage up to 0.30v higher than the default voltage. It is best to read up on the latest reviews about overclocking a specific CPU to find out what others have done and what is the suggested maximum voltage to use. Remember that increasing the core voltage will also increase the heat output so only raise it as high as is necessary, but of course you usually end up maxing out the voltage to get the max speed. * Overheating - An inexpensive way to check if heroic cooling will help overclocking stability. Use a can of "freeze down" electronic component cooler. Spray the coolant directly on the CPU. A $6 USA can (about 14 ounces) is enough to keep an Intel CPU well below 0 C for 5 minutes while operating under load. Most good electronic supply houses will carry it. Radio Shack also has "freeze down"; Cat. No. 64-4321 "Component Cooler", but the Radio Shack price is $6.99 for only 4.5 ounces. Thanx to Phil Weldon! * PCI or AGP bus running to fast. Keep the PCI bus as close to 33Mhz and the AGP as close to 66Mhz as possible. Too fast can cause other components beside your CPU to freak and lock the system. This is all dependent on the PCI and AGP dividers being used. For Example – 133Mhz FSB x 1/4 PCI Divider = 33Mhz * Poor quality memory, or memory just not made to run fast. High quality PC133 is recommended for a good overclocking system. You can use PC100 memory if your sticking with low FSB’s 124Mhz or lower. Try setting the memory timings (CAS/RAS/etc.) to 3. Setting the memory timing to 2 is faster, but can cause some instability if the memory cannot handle it. DDR memory also applies to this, use PC2100 (266Mhz) or PC2400 (300Mhz) memory to be sure you have plenty of overclocking room. * Update your BIOS and drivers for all your system components!! * Some people have reported strange problems and instability being fixed by using a different Slotket made by a different manufacturer. If your using a Slotket made by Soyo, try one from Asus, you get the idea. Just because it was made by the same manufacturer, that doesn't mean it will work well when you start overclocking. (Thanks to "ericvq@my-deja.com" for letting us know his Soyo Slotket would not work on his Soyo board when he started overclocking) Q: My Motherboard doesn't have any core voltage adjustments, how can I change the voltage? A: Intel: It is possible to change the voltage by altering the signals from the CPU to the motherboard. Slot 1 Motherboard - there are three things you can do: 1. If your using a Slot 1 board and a Slotket, you can use a Slotket that has voltage jumpers on it to set the voltage. The CPU sends a signal to the motherboard to tell it what voltage the CPU needs (ex - 1.65v). The Slotket can intercept this signal and change it according to the jumpers set on it (ex - 1.80v). So the motherboard will see the voltage signal from the Slotket and not the CPU. The motherboard will then set the voltage according to what the Slotket told it to use (ex. 1.80v). If you leave the jumpers on the Slotket set to Auto, the voltage signal is not changed in any way. 2. If your using a Slot 1 board and a Slotket with NO voltage jumpers on it, just use the same wire wrapping trick for a Socket 370 CPU. 3. There is a way you can tape the pins on a Slot 1 CPU or Slotket to alter the voltage signals. Follow these links for an explanation of this procedure... (The PIII Slot1 pinouts are the same as the Celeron and PII) Adjusting the Celeron Core Voltage by taping pins Slot 1 Voltage Selection for ANY Motherboard AMD: It is possible to change the core voltage by changing the L7 Bridges on the Socket A CPUs. Tom's Hardware has a great article about this. Q: I can’t get higher than 1.70v for my core voltage in the BIOS? A: Most motherboards limit the adjustment you can change the core voltage too. You can use one of the procedures in the previous question to make the motherboard think the default voltage is higher. If the original default voltage is 1.50v and you trick the motherboard into thinking the default voltage is 1.80v, you will then have a higher range of voltages to choose from. You will still have full control over your voltage settings in the BIOS, just with a higher range. You may be able to use the BIOS flash trick as listed on some of the Abit Motherboard FAQ sites. I stole this part from the BH6 site, Thanx to Luke Carroll! - Set the voltage in the bios to the max you can get, i.e. 1.7v. Follow the bios flashing instructions in Bios Info, but type 'awdflash /cc bh6_xx.bin' to use the /cc parameter. That is for an Abit BH6, but it works for some other Abit boards also. Just substitute the BIOS version in where it shows bh6_xx.bin. Read your manual or go to the motherboard manufacturer's site for more info. There are also voltage mods you can do on your motherboard to obtain higher core voltages. Check www.overclockers.com for more info. Q: I flashed my BIOS with the wrong version or something went wrong and now my board is dead! A: Your BIOS is probably scrambled, here are a few solutions: * Try clearing the CMOS with the jumper on your motherboard. This probably won’t work, but it’s worth a shot. * You can order a new BIOS Chip from the motherboard manufacturer or from a place like http://www.badflash.com/. * There is a process called ‘hot swapping’ where you can swap BIOS chips with a board that has the same chip as the hosed one, flash it, then pop it back into your motherboard. The site for the BE6-II below explains this more. Q: How can I check the temperature of my CPU? A: All the Pentium II, III, and Celeron CPU’s have a diode built into the CPU that can allow the motherboard to sense the temperature of the CPU. The AMD XP CPUs now have a thermal diode built into the CPU. NONE of the other AMD CPUs do. Some AMD motherboards have a thermistor under the CPU that will read the CPU temp. Your Motherboard must support this feature also. The best way to tell if it does is look in the BIOS for a CPU temp listing. You can use one of the shareware programs on the links page to see the temp in windows. You may also want to look at calibrating your motherboard to read the proper CPU temp. Q: How hot should my CPU be? A: The temp limits shown by AMD and Intel are the absolute limits that the CPU can handle before it is destroyed. This is by no means a guide to go by when looking for a normal operating temperature! If your CPU were to even approach 80C it would most likely lockup before it destroyed itself. Most CPU’s (under idle conditions) should not be running above 50C (122F). 40C (104F) is a good temp to shoot for. Obviously, the cooler the better. A cooler running CPU will last much longer, and lessens the chance of crashing the system. A CPU is made up of transistors, when a transistor gets hot, it tends to leak current. Too much leakage can result in calculation errors, too many errors will cause a crash. More speed equals more heat. More heat equals more crashes. More cooling means less errors/ less crashes/ more speed (to a certain point anyway). Your system (motherboard) temp should be fairly close to room temperature, within 5C (9F) degrees or so. If the system temp is higher than that, try adding more case cooling (see below). Q: My CPU seems to be running hot! What can I do? (Cooling Info) A: There are a few things to look at: * Remove the HSF (Heatsink/Fan) and make sure you are using a thin film of heatsink compound. This is easily found at Radio Shack or other electronics stores. Thermal pads are not as good as compound!!!! * Be sure you have good case ventilation. It will do you no good to have a good HSF setup but nowhere for the heat to go! You should have at least 2 fans exchanging air in your case. One blowing in (normally in the front of the case), one blowing out (the power supply fan can be one). Be sure and try to balance the amount of incoming and outgoing airflow, or have enough vents so air can escape or enter the case freely. * Check to make sure the HSF is fitting on the CPU properly. Some HSF’s don’t fit to well on the FC-PGA CPU’s, they can tilt to one side or the other. Most Socket-A CPU’s (T-Bird, Duron, etc) have little cushions to help stabilize the HSF on the CPU. * Get a better HSF. Alpha, GlobalWin, and Thermaltake are all good names to look for. If your HSF is not good enough, then the only way to cool off is to upgrade. A Peltier setup is also an excellent way to keep your CPU temp way down. * Q: What is thermal grease/compound? How do I apply it? A: What it is - Thermal grease/compound/paste is a substance that promotes the conduction of heat between two surfaces by filling in small imperfections in the materials that would otherwise create an air gap. It is not nearly as effective as touching metal to metal, but is a better heat conductor than air. You only need to use a very thin film to fill the small gaps. This link has a good explanation: The Heatsink Guide: Thermal interface materials Applying - Clean the CPU and HSF with alcohol (Isopropyl, not beer, whiskey, etc..) and let dry. Put a very small dab of compound on the CPU die and spread it so there is a very thin film on the CPU. DO NOT put it anywhere that the CPU does not touch the HSF directly. You can use your finger, but its best to use something that will not contaminate the compound with oils from your skin. A credit card or razor blade is recommended. The ArticSilver site that shows a lengthy explanantion of this, look under Product Instructions. There is more about why to use this goop on the Cooling Tips page. Q: What is a Peltier? A: Peltier devices, also known as thermoelectric (TE) modules, are small solid-state devices that function as heat pumps. Go to these sites www.tellurex.com , www.peltier-info.com for a complete explanation. Keep in mind that for the best cooling, the heatsink for a Peltier CPU cooler must handle THREE times as much heat as the CPU produces. Q: How far can I expect this CPU to overclock? A: Here are some typical max speeds you can expect: * Intel Celeron, original Mendocino Core, 533 and lower - 590-600Mhz * Intel Celeron, new Coppermine cB0 Core, 533a and higher - 900-950Mhz * Intel Celeron, new Coppermine cC0 Core, 533a and higher - 950-1100+Mhz * Intel PIII Katmai - 600-650Mhz * Intel PIII Coppermine, cA2 Core - 800-850Mhz * Intel PIII Coppermine, cB0 Core - 900-950Mhz * Intel PIII Coppermine, cC0 Core - 950-1100+Mhz * AMD K6-2, newer CPU's - 550-600Mhz * AMD K6-III - 450-500Mhz * AMD Duron - 900+ Mhz * AMD Athlon - Varies allot!, check the databases. You can also check out Overclocker.com's CPU Database. The average speed will give you a good idea of what you can expect. Always remember not all CPU's are created equal! Some overclock very easily and some just won't do it no matter how hard you try. It's luck of the draw, but you can increase your chances by reading up on the latest news and buying a CPU that has the best reputation. Q: What is a Slotket? A: A Slotket is an adapter to allow a Socket 370 CPU to be used in a Slot 1 motherboard. This can be very handy if you have one that will allow FSB or core voltage changes via jumpers on the Slotket. If you have a motherboard that does not allow the FSB or core voltage to be changed on the motherboard, you can use the Slotket to change them. The Slotket can intercept the FSB and core voltage signals from the CPU to the motherboard and change them to make the motherboard think the FSB or core voltage is higher (or lower). BUT, if the motherboard DOES have the ability to manually change the FSB and/or core voltage, the motherboard has the final say in what settings will be used. Slotket = Slot to Socket adapter = SLOT + socKET Q: What is Stepping? How do I tell what core a CPU has? (CPU Information) A: Intel's definition - The “stepping” number indicates design or manufacturing revision data for production Intel microprocessors (e.g. Stepping 4). Stepping is used to indicate a “revision”. By using unique steppings, it facilitates change control and tracking. Stepping also allows an end user to identify more specifically which version of the processor their system contains. This classification data may be needed by Intel when trying to determine the microprocessor’s internal design or manufacturing characteristics. SO... Stepping is the Core revision of a CPU. It is always best to try and get the latest core revision. As improvements are made in the core, it allows the CPU to run at faster speeds. Q: Is ‘this’ CPU faster than ‘that’ CPU? (PIII vs. Celeron vs. Athlon vs. Duron vs. Etc..) A: Check out the reviews at the many sites dedicated to testing computer hardware. They give excellent info and easy to read charts on just about any CPU your thinking of getting. Anandtech is a great place to start, look for the CPU reviews. Remember, the CPU is not the only factor in determining how fast a computer will run. If the Video Card or other components are crap, your overall performance will be crap. Q: Can you recommend a Motherboard or CPU or System for overclocking? A: This changes almost weekly! The best thing you can do is go to the hardware review sites and READ the latest reviews. This way you can learn the latest info faster than you could get a reply on the newsgroup. Also do some comparisons of prices and how far each CPU can overclock, this will tell you what the best value is. If you want a system that will be exactly what you want, then YOU need to make the decision and not base it on others opinions. Here is a step by step of how I built a system for overclocking. This may help you to make decisions of what to look for. Q: How can I test an ATX power supply or manually turn it on to use it as a power source? A: You need to tell the power supply to turn on. This is done by the motherboard when using an ATX power supply. So if you can send the signal to the power supply manually, you can turn it on using the same pin as the motherboard uses. The pin is the Power_On pin, not the Power_OK or Power_Good pin. There is no specification as to color of the wires, but the Power_On pin is pin #14. The motherboard turns the power supply on by toggling the signal to this pin #14 to a low level. Ground will do, so connecting any of the ground pins on the power supply connector to Pin # 14 will do (Pins 13, 15, 16, 17, 3, 5, and 7 are Ground or Common.) The motherboard is able to toggle the level of this signal when the front panel ON switch is pushed. This is possible because, for an ATX power supply, the Standby + 5 volt line is always powered as long as the power cord is plugged into AC power. The Power_OK or Power_Good Pin is pin # 8, it is a signal FROM the power supply that tells the motherboard that the voltages are ok. Since the ATX and AT power supplies are switching power supplies, it is sometimes necessary for a significant amount of current to be drawn from the + 5 volt line; else the + 12 volt line will not be regulated and will supply very little current and even that at a low voltage. If you have such a power supply, it is necessary to put a 10 to 20 watt dummy load between one of the + 5 volt pins (19, 20, 4, or 6) and one of the Ground pins. Thanx to Phil Weldon! Q: How do I run a Quake Timedemo or Demo Loop to stress my computer? A: To run a Timedemo in Quake, use the following commands in the console (press the ~ key (below ESC key) to drop down the console). Enter the command and hit enter, if you did it right, then it will not say anything back. If you type it wrong it will let you know. Quake 1 - timedemo demo1 - You can substitute any demo for demo 1, like timedemo demo2. The demo will begin immediately, raise the console when it starts. Quake 2, 3 - timedemo 1 - Then start any demo and it will run in timedemo mode, type timedemo 0 to turn it off To run Quake 3 in a loop to stress test your computer.. type in the following commands: timedemo 1 set demo1 "demo demo001; set nextdemo vstr demo2" set demo2 "demo demo002; set nextdemo vstr demo1" vstr demo1 You can also jump straight into the timedemo loop by using this shortcut. You will have to change the directory to the directory that Quake 3 is loaded into on your computer... Quake III Timedemo Q: How can I make my fans run quieter? A: High RPM fans are very loud, one classic example is the 60mm 38CFM Delta fan. It is famous for it's huge amount of airflow to cool CPU heatsinks, but even more for the incredible noise it produces. You can change the voltage that the fan is running on to make it run slower. This will create less noise, but also remember it reduces the amount of airflow considerably and may make the high dollar fan you just bought run slower than the cheaper one you passed up on. You can reduce the voltage two ways: 1 - If your using a 4 pin fan (4 pin plug, 2 wires) then you can simply swap the wires around to give the fan either 7v or 5v to make it run slower. You first need to know what the color code of the wires are. A standard 4 pin Molex connector from a power supply has 4 wires attached. The Yellow wire is +12v, the Red is +5v and the 2 Black wires are both ground (connected together inside the power supply). A normal 12v fan uses the Yellow and Black wires to get +12v. If you use the Yellow and Red wires, this will give you +7v (12 - 5 = 7). If you use the Red and Black wires, this will give you +5v. What you need to do is figure out which pin to remove and move to the proper spot to give you the voltage you want to run. The Plug that goes to the fan should only have 2 wires in it, a yellow and black. These connect up to the yellow and black on the power supply plug side. For example, if I decide I want to run my fan at +5v, then remove the pin that is connecting the yellow fan wire to the yellow +12v wire and move it over to connect to the red +5v wire. Leave the black wire connecting to the black wire. Once you know what pin your going to move, you can do the following to remove and reinsert the pin(s). If you look at the pins inside the male plug (fan side), you'll see what looks like two flaps that have been spread out from the sides of the pins. This is what holds the pin into the plug. Using a very small flat head screwdriver, flatten the flaps down toward the pin so the pin can slide out of the plug. Spread the flaps back out a little bit before you insert the pin again so it will lock back into place when you re-insert the pin. Insert the pin back into the plug so it will line up with the proper wire you want to use. 2 - You can use what is called a Potentiometer or Rheostat (I'll just use 'Pot' for short) to vary the voltage to the fan. A Pot has variable resistance which will control the amount of voltage that is supplied to the fan. If you increase the resistance, it decreases the amount of voltage supplied to the fan. All you have to do is wire the Pot in series with the fan. This can be done with 4 or 3 pin fans. Just cut the yellow (or which ever is the +12v wire) fan wire and splice in the Pot. Put the wire to the fan on one of the outside connectors and one to the plug on the center. Your typical Pot can not handle very high amounts of current so you generally need a high wattage Pot if your going to be using it with a high RPM fan or multiple fans. You can figure the wattage you'll need by this formula: Power (watts) = I (current) x E (voltage) For Example, a typical 80mm fan that is labeled .18 Amps and runs at +12v. This gives us about 2.1W. So you would want to get a Pot rated for at least 5 Watts. A good place to get high wattage Pots is from Digi-Key (search for Rheostat, 50 ohms works well). Just beware that a good Pot is going to cost you a bit. Q: Should I 'burn in' my system before overclocking? A: The only real reason to do a 'burn in' is to make sure all your system components are working properly before you start overclocking. The CPU does not need to be broken in, there are no moving parts like an engine so there is not any friction producing parts that are going to be damaged by cranking up the core speed prematurely. If you are just changing out your CPU in an already stable system, then just check it out to be sure the heatsink is on good (the temps are normal), and the system boots and runs stable under some stress. Then crank her up and see how far she'll go! Q: I have an Abit motherboard and it has become unstable or won't boot sometimes, help? A: Check the capacitors (little can looking things) around the CPU slot/socket to see if any are leaking or bulged at the top. If any are leaking, you will see a little brown residue on top of them. If they are bulged up, this may mean they are getting ready to 'pop' next time they get hot enough. This is a known problem with some Abit motherboards. My Abit BE6-II ran great for about a year until suddenly it would not boot until I reset it about 10 times. I found the three 'caps' nearest the slot had leaked, I replaced all three and my problems were solved. This does require some good soldering skills, but in general it is not that difficult to do. Just unsolder the bad ones, and solder in the new ones. Obviously if your board is still under warranty it would be better to get it replaced.
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