This is the first part since I can't cover all of them in one night. Feel free to add your suggestions, comments and recommendations if I missed any. I'm not an expert on computers but add years of experience and I bet I can contribute something to 'our' community. This thread will cover lots of grounds on overclocking and hopefully, will be friendly to newbies and hardened overclockers, alike. For those interested in the topic, please keep it alive as I will be editing the additional information rather than posting them as replies. Also, I am not taking full credit of this post as most of them are collections of what I read on the internets + my own interpretation and experience.
Let's start with a disclaimer, shall we?
Istorya.Net, the thread starter and the subsequent responders or contributors will not be held liable for damages incurred while trying out steps on this thread. You are doing this at your own risk, if you run into problems on the course of you overclocking, I or we will help you to the best that we can but only up to that point. Rest assured if you take the necessary precautions and suggested approach, you're overclocking would be silky-smooth.
I. RATIONALE
Why overclock? My answer is, why not? I can probably point out lots of reasons but I'll narrow it down and keep it simple.
- Additional Knowledge. Sure, sure, you're a computer graduate but do you really know your computer well and computers in general? There's no harm in expanding your horizons, only burned-out parts...just kidding.
- Optimize. Not many of us can afford high-end rigs where overclocking would be pointless. Why not, get the best out of your computer? If you'd argue about shortening the life of it, I'd say, do you intend to use the same old computer in the next 5 years that you worry about shortening its life? If not, then this thread is for you.
- Bragging rights. Err, to put it professionally, the word would be benchmarking. You'd be like, dude, I've overclocked my computer 3 MHz up and your friends would say, 'that is so cool, bro'. I can't guarantee you'd get chicks with this approach as my officemates or friends would just nod and say 'okay'. 'Nuff said.
II. DEFINITION OF TERMS (lots of reading, less action - read and understand as this will be the basis of overclocking)
Overclocking - is the process of forcing a computer component to run at a higher clock rate (more clock cycles per second) than it was designed for or was designated by the manufacturer, usually practiced by personal computer enthusiasts seeking an increase in the performance of their computers. (thank you,
Wikipedia.)
Processor Clock Speed - the processing power of a CPU measured in instructions per second, MHz (megahertz) or GHz (gigahertz). (thank you,
Google.)
This is also known as the speed of the L2 Cache and is obtained using the formula 'CPU Clock Multiplier or Core Ratio x CPU Front Side Bus'. If for example you have an E8400 processor, the clock speed 3 GHz was obtained because the E8400 has a clock ratio of 8 multiplied by the front side bus which is 333 MHz. Furthermore, what you see on the flashy boxes of processor isn't the actual processor speed, what you see is the effective clock speed. If we are to break everything down using the E8400 as an example, we simply divide the effective clockspeed to its core ratio (9) and we get the actual speed. For more information, check with your processor documentation or visit the manufacturer's website. Now the next thing you probably have in mind is...
CPU Front-Side Bus - In personal computers, the Front Side Bus (FSB) is the bus that carries data between the CPU and the northbridge. (once again, thank you
Wikipedia) Do check the website as it contains a picture of what and where the front side bus is.
This is also the part that we are overclocking. We raise this to a certain value x the core ratio = your new and overclocked speed. However, do not get confused by the labels on the motherboard that says "front-side bus". What is labeled there is the "effective front side bus the motherboard supports". Think of the CPU FSB as the gate and think of the FSB on the motherboard as the road. Now, its formula is CPU FSB x 4 since Intel processors are quad-pumped, meaning, it sends out data 4 times in a cycle. Using the E8400 as an example, '333 x 4 = 1332 <--- motherboard front side bus'. If your motherboard supports 1333 Mhz FSB, it means that it can support the E8400 easily without problems and without any further changes to the BIOS.
Core Ratio / CPU Multiplier - This thing happens inside the processor itself. From my understanding, before the processor spits out data, it has an internal multiplier that effectively increases the power of the front-side bus. Again, with a processor that has 333 MHz FSB and a core ratio of 9 will give you 3 GHz, the effective clock speed, yay!
CPU Vcore/VID - the voltage that your processor operates on. This is critical in overclocking, read about your VID range before overclocking. Check with manufacturer's website, its all there. Raising this voltage also increases your temperature, which also true as for the rest of your components.
Northbridge - The northbridge is your chipset (in case you didn't know that, you know P35, X38, P45, X48, etc.) Okay, the northbridge links your processor and your memory and the rest of your system (southbridge holds the hard drive, I/O ports, BIOS, etc.). Put it this way, if you expand your gate, you also need to widen your road to accomodate the added load right? The chipset handles that for you. Take note though that as you go higher up in FSB, the northbridge chipset would become unstable and will require more juice (voltage).
NB Core - the voltage that your northbridge chipset is running. Also critical in overclocking.
NorthBridge (NB) or FSB Strap - The NB Strap is clearly defined and explained
here, but to keep it simple I'll use examples. As you increase your CPU FSB, the overall front-side bus is affected right? The strap contains controls of your memory latencies (later) to keep the system stable. You may have excellent memory response at certain straps (1066 MHz) but not on a higher strap (1600 Mhz).
PCIE Speed - You might ask, how in hell did PCIE got in here? Simple, the PCI Express is directly connected to the NorthBridge chipset. If you increase the FSB, you're also increasing the PCIE speed. Don't worry much as most motherboards have the option for you to lock this at a certain setting (100 MHz) -- default.
Memory (DDR2) - this is where the programs are loaded for faster access from the CPU. DDR stands for Double Data Rate, if we want to know the exact frequency of a memory we simply divide it by 2. For example, if you have a DDR2-800 memory, divide the 800 by 2 and you get 400 Mhz --- the actual memory frequency. More information
here. Take note of your memory voltage as this will be needed if you overclock your memory. Remember, if you are overclocking the FSB, you are also overclocking the rest of your components (northbridge chipset, memory).
Memory Latency/Timing - the time that your memory responds to data. This is the number that you see on CPU-Z (5-5-5-15, 4-4-4-12-16). As you tighten the settings, the memory would become unstable requiring more voltage. What good is it if you have high FSBs but your memory is not responding as fast as it should be. NOTE: This thing is very fragile specially if you overvolt it. Unlike the processor that can take a beating, this one is very sensitive so always determine your memory voltage.
Memory Divider/Memory Multiplier - Remember what I said about the memory being fragile little things? This option will help you out. By now, you know that the processor can take a beating but not the memory. The memory divider is a feature in your chipset that allows you to raise your FSB as much as you can without affecting your memory...much. This is also the reason why overclockers choose high frequency memory to give them lots of headroom on the front-side bus for overclocking. Now, here's
a very good article that covers this feature.
This is how its calculated:
Say for example we have an E8400 (FSB = 333 MHz) at 1:1 memory divider, our memory would operate as 333 Mhz. Simply divide the 1 to 1 then multiply by your FSB and you get your memory frequency. What if we change the divider to 1:2, at what frequency will our memory operate? 2/1 * 333 = 416.25. Now, double the 416 (double data rate) and if you have a DDR2-800 RAM, you're already slightly overclocking it at DDR2-833, this might not be stable with stock voltage so choose the appropriate dividers that will equal to the RAM that you have.
For memory multipliers, its a direct-to-approach. Say you motherboard has a 2.5 memory multiplier, multiply that to your fsb and you get the memory frequency -- 832.5, (no need to double as this will determine your memory frequency right away). Again, use this to stabilize your overclock.
III. TOOLS and UTILITIES
Okay, its obvious that you're going to need the computer. Nevertheless, I'll include the computer components here to clarify a few issues as well as programs that you're going to need to test the stability of your overclock. Your overclocking by the way, directly affects certain components:
- Processor - must be from the 'conroe' series. The Prescott processors are just way too hot to handle, even at stock settings. How do you know the codename for the processor, there is a tool available later on that we're going to use. In addition, if your processor has E or Q followed by a group of numbers, then these are the 'conroes'.
- Northbridge Chipset - there are numerours chipsets available (VIA, SIS, AMD, NVIDIA, etc.), you're going to need a chipset that is built for performance (this statement rules out VIA and SIS) and can take a beating. Intel's P965 and X series above with the exception of the G which stands for general use are nice and very good chipsets. ATI also has a chipset before it was bought by AMD, the RS600 which sports a full asynchronous memory (only available to a DFI motherboard). Lastly we have NVIDIA's, the 680i above are overall, nice overclockers.
- Memory - Like I said earlier, choose a memory that will give a lot of overclocking headroom. If you read the links on the previous part, you'll see there that the memory frequency is half of the actual frequency. Don't choose a memory that will limit you overclocking, for example; DDR2-400 which actually runs at 200 MHz, most of the processors I mentioned already has this frequency if not, higher. You'll have a hard time raising your FSB and your memory multiplier (where applicable) to this amount.
Indirect important components are:
- Power Supply Unit - No, your unknown generic power supply wouldn't cut it. We'll be fine tuning voltage cores to the finest of details, I simply can't stress enough how important you're PSU is going to be. Just like the memory, just one that will give you headrooms for the changes of power loads but be practical. You're not going to buy a 1K Watt PSU for a single card configuration and a few MHz overclock, are you?
- Cooling - Cranking up different components raises their respective temperatures. This is mostly applicable to the processor and chipset area. As long as you keep the memory in its specifications you're not going to need a cooler for it. If you don't overclock/overvolt the memory, the memory frequency will be the limit to your front side bus. Now if you don't get a decent cooling for the processor, your processor temperature will be the limit of your overclocking as well. Search around the forums, you'll find great deals for coolers.
IMPORTANT PROGRAMS THAT YOU (MAY) NEED:
CPU-Z. This for me, is the best application to know the ins and outs of your processor. It'll show you the family of the processor, the voltage it runs at, front side bus, core speed, clock speed, memory frequency, timings, even instruction sets. It also give you the option to take a screenshot out of your settings, upload it to their hosting site for you to brag about.
Core Temp. They say this is the program that has the most accurate readings of your core temperature.
HW Monitor. This is a all-in-one utility that keeps tracks of temperatures and voltages for majority of the components of your computer.
OCCT. A program for stressing your computer useful for determining errors in the first few minutes/hours of your overclocking. Its a utility that not only stresses your system but can track your voltages, temperature and even provide a graph if the program was stopped due to stability.
SP2004 ORTHOS EDITION. This for me, is the best long-time stress-testing your computer. It is made from Prime95 but given a much nicer GUI.
<INSERT BENCHMARKING TOOLS HERE>. Choose any that you like, SiSoft Sandra, PCMarkVantage, etc. For the lazy type, like me. I simply make use of Window's Vista's User Experience Index. Don't take it lightly, different configuration raises certain points.
IV. OVERCLOCKING FOR MORE PERFORMANCE
This, I should say is the best part of overclocking but don't take it lightly. This part requires patience...LOTS of PATIENCE. You can even say patience of a monk but jokes aside, your overclocking may take several days which is why you need patience. Anyway, there are 2 ways you can get yourself to a stable overclock, i'd say pure bruteforce and slow as a snail.
BEFORE YOU BEGIN
- Be familiar with your BIOS. Know each setting that is related to performance and where the terms defined here are applicable.
- At this point, your vcore and everything else is set to auto and I'm sure your mobo has a pc health status where it will show the current voltages and temperature. Take note of your current vcore, and your current temperature. This will determine how much you can squeeze out of your processor with respect to its vcore range.
Low processor vcore is pure luck. Some processors upon point of sale may already be running at a high vcore value which will limit your overclocking. If what you have is quite high, there's not much you can do except to accept the fact that its running at that voltage. Your mileage will vary as no two processor run at the same voltage. My E4500, is already running at 1.32v, a quick google search and I even found results with their vcore running as low as 1.2, lucky bastards.
- Boot to windows, open CPU-Z or HWMonitor and check your vcore. You'll find a somewhat lower voltage as to what is shown in your BIOS, this is not a malfunction but a feature called vdrop. What you see right now is the vdrop on idle. Now, run a short stress test (15-30 minutes) with your favorite program while checking your vcore, it'll go lower than what you've seen earlier. This is your vcore under load. Take note of these values as they will be helpful later on once you start cranking up your voltage.
- We're still at stock settings, run your favorite benchmark utility. If you're on Windows Vista, keep it simple, run the Windows Experience Index, take note of your scores most specifically from the CPU and Memory as these items are directly affected with changes to the Front-Side Bus.
- Set a goal for your overclock (clockspeed). I mentioned earlier that I would recommend a memory of DDR2-800 or higher, which will give us huge headroom for the front-side bus at 1:1.
Method A: CRANK UP THAT FRONT-SIDE BUS
- Lock your PCI Express Speed at 100MHz (default) and your PCI speed at 33MHz (default). Leave your memory speed and timing to AUTO or SPD, this will rule out the memory as the culprit if the overclock is unstable. We will work on the timings later. Set memory divider at 1:1. Leave everything else at stock settings, for now.
- Raise your CPU front-side bus by 20 MHz (or bit higher if you're impatient, LOL. say, 30 MHz?).
- Boot to Windows, log your processor temperature and run a short stress test (15 to 30 minutes with OCCT). If stable, reboot to BIOS, raising the front-side bus each time it passes your stress test until unstable.
SYMPTOMS of an UNSTABLE OVERCLOCK
- Stress-Utility crashes
- System doesn't boot to Windows.
- Stop Error a.k.a Blue Screen
- Computer Locks up or restarts
- If the computer shows any of the symptoms shown above, this is your cue to raise your processor voltage. Raise it to the next step, if stable, perform another short stress test and move on to the next increment for your front-side bus until you've reached about 75% of your maximum vcore voltage.
This approach is more focused on the processor since we cannot raise the front-side bus much using the default core ratio or cpu multiplier. If you think that you've reached about 75% of your vcore range, try adding a notch higher to your northbridge core, if it doesn't make difference, reload default settings.
- Drop your core ratio/cpu multiplier then perform the same increments with your front-side bus each time, stress-testing your computer for stability. If the computer is still unstable and you think that you've given it a reasonable increase in voltage, try raising the northbridge voltage at the next available increment. Remember that the higher FSB you have, your chipset would require additional voltage. Keep the chipset voltage reasonable and ALWAYS WATCH YOUR TEMPERATURES.
I'll use my processor as an example. E4500 runs at the following default settings: 200 MHz FSB, 11x Core Ratio , VID: 0.85V – 1.5V
At the stock-setting benchmark, processor was 5.0 while memory yields 4.8. Leaving the Core Ratio at 11, I can only go as high as 280 MHz FSB with 1.45v VCore which gives me a 3.0 GHz overall clockspeed. At this setting, Windows Experience Index gives my processor a score of 5.7 and a memory score of 5.1. Temperature-wise this gives me about 38c on idle and 58-62c on load (cooled by Arctic Freezer 7 Pro).
Now, I dropped the core ratio to 10 and at this point I can now move on to 295 MHz FSB with 1.39 VCore and stock setting for northbridge chipset voltage. This approach gives me 2.95 GHz clockspeed and the same range for the temperature. Windows Experience Index Score, CPU: 5.7 while memory is not at 5.3. I've tried many configurations after this one pretty much giving me the same results and scores. To put it short, since I was aiming for a 3.0 GHz clockspeed, I dropped the core ratio all the way down to 9 and raised the front-side bus to 333 Mhz putting it a 1:1 ratio since I'm using a DDR2-667 memory.
I have to admit the board I'm using is awesome as the front-side bus is completely asynchronous to the memory which means that no matter how much I raise the FSB, memory frequency would stay the same (thank you, mE_bytes) still, I opted for a 1:1 ratio. This method gives me the same temperature range on the processor, a slightly higher chipset temperature (75-80c O_o). Vcore at this point is at 1.43v, northbridge voltage is at 1.38. This is where it gets interesting, Windows Experience Index now gives me a Processor score of 5.6 from 5.7 while memory score is not at 5.5. To conclude, the higher your front-side bus frequency is, the more you get out of performance.
Method B: Skyhigh with Voltages
This is an overclock with a goal in mind. Try not to think way overboard with this one as it is a bit dangerous and risky. Make sure you have sufficient cooling too as we are starting from the top with voltages, and slowly going down. You should know by now the maximum VID range for your components.
- Raise all voltages for your northbridge and processor to its maximum VID range.
- Raise FSB to your target, then boot to Windows. Run a short stress test.
- Be very mindful of your temperature. If the system still doesn't boot or still unstable, then your target is too high and with the amount of voltage you have by now, it is by no means achievable without overvolting your processor. If this is the case, lower down your target until stable.
- If at a certain setting the system is completely stable, start lowering down your voltages until the system doesn't boot anymore then, get back to the previous setting. Easy as that.
- Run an hour or two of your stress test program.
V. MEMORY TIMINGS
I'm not too good at this particular topic, so if you have additions, I'd be happy to add it in here. IF you're not familiar with what memory timings are, this is the amount of time your memory responds to data being requested or sent to and from the processor. What good is it when you have a faster memory bandwidth but slow response, right? Memory timing is maximizing the overall potential of your overclocked front-side bus.
If you open CPU-Z, you'll basically find one of the tabs that says Memory. Further down, you'll see values that says and if arranged in a line will look like this: 4-4-4-12-16. The CAS# Latency and the Command Rate are the 2 very important things you need to lower down here. The rest is, err, not that important but if you can lower down the overall timings, the better.
Lower down the CAS# Latency and the rest of the setting one point (proportional) at a time. If it doesn't boot, revert back to the previous setting. If it doesn't POST, then obviously, the timings are too tight. If you're up to it, increase the voltage of your memory but keep it within specifications. Value RAMs are usually at 1.8v while enthusiast or performance RAMs can go as high as 2.4v, again, keep it within specifications. With each changes in the setting, boot to Windows and perform an hour of stress test (focus the test to the memory). I saved the memory for last to isolate it if in case you'll have problems on the course of raising the front-side bus, the memory isn't part of the problem. As I said, the memory, unlike the processor is quite sensitive to overclocking which is we started with loose timings on the memory letting the northbridge decide what's best for it according to the fsb-strap.
TIP: if your bios has options to save an OC profile, save your settings prior to making changes to the timings as there would be no fix for the system not posting in case of tight memory timings but only by clearing the CMOS. If it doesn't have that feature, then take note of your current settings.
VI. STRESS-TESTING YOUR OVERCLOCK
This is the most boring part but VERY crucial. Most people would recommend running a stress-test for 24 hours but in my opinion, this is only applicable to the people who have their systems running 24/7. If you're not this type, then run a test as to how long you usually use the computer. For example, if your daily usage is 5-8 hours, then a stress test of the same timeframe is sufficient.
My recommendation: ORTHOS STRESS PRIME (Priority
or Prime95.
A Comprehensive Guide To Overclocking Intel Processors
Originally Posted by mejie
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