CPU Overclocking Guide: How (and Why) to Tweak Your Processor
Learn the pros and cons of overclocking your CPU, the physics behind changing your clock rate and the basics of overclocking an Intel or AMD processor.
Benchmarks and Comparisons
Just for fun, we compiled a list of overclocked systems from various users online. This list is by no means exhaustive or up-to-date, nor is it meant as a guide. It is just a sample of what is possible.
Selected Overclocked “World Record” builds, Source: CPU-Z Validator
System Builder | CPU | Stock Speed | Overclocked Speed | Vcore | Motherboard |
---|---|---|---|---|---|
Andre Yang | AMD FX-8350 | 4.0 GHz | 8.794 GHz | 2.064 V | Asus Crosshair V Formula-Z |
DIBILOX-PC | Intel Core i7-860 | 2.80 GHz | 8.510 GHz | 1.152 V | Dell 0T568R |
HKEPC | Intel Core i7-6700K | 4.20 GHz | 6.998 GHz | 1.888 V | ASRock Z170 OC Formula |
FtW 420 | AMD Phenom II X4 955 | 3.0 GHz | 7.193 GHz | 1.872 V | Asus Crosshair V Formula |
Splmann Team Ocaholic | Intel Core i7-3770K | 3.5 GHz | 7.247 GHz | 1.792 V | Asus Maximus V Extreme |
CherV@HKEPC Lab | AMD A10-6800K | 4.4 GHz | 8.519 GHz | 1.984 V | ASRock FM2A88X Extreme6+ |
A Final Note on Cooling, Sensors and Maximum Temperatures
The actual components of the CPU—metal, silicon, and adhesives—are all rated for temperatures above 95+ °C, and no component degradation (short term; we’re not discussing electromigration here) should take place below this limit. However, most processors have a thermal shut-down limit around 90 °C, and while it is possible to run a processor near these temperatures, it’s not very healthy for the CPU or platform.
It should be noted that the socket temperature is not the same as the CPU core temperature. AMD CPUs do not have a thermal probe, and the CPU temperature displayed (through Overdrive or another utility) is an algorithmically calculated value from the socket temperature sensor. The inverse holds for Intel processors: Intel does not have a socket temperature sensor, and relies on thermal probes in the CPU to provide information. The distinction between the two temperatures only becomes relevant for very demanding performance and benchmarking scenarios. Socket temperatures can get quite high if the voltage regulation cooling is not quite as effective as the primary CPU cooling, and some overclockers have reported that cooling down the socket itself with a fan placed behind the CPU main fan, blowing over the motherboard, can help in such scenarios.
Another difference between AMD and Intel is that AMD processors do not handle high temperatures well. Take a look at the table below to get an idea of thermal thresholds on some high-end processor models.
Processor | Maximum Temperature (CPU) | Maximum Temperature (Socket) | Maximum peak temperature reported |
---|---|---|---|
Intel Core i5-6600K | 95 to 100 °C | N/A | 55 °C |
Intel Core i7-6700k | 95 to 100 °C | N/A | 73 °C |
AMD FX-8370 | 65 °C | 72 °C | 62 °C |
AMD A10-7890K | 65 °C | 72 °C | 60 °C |
Effectively cooling the CPU components is integral to the art of overclocking. Tom’s Hardware has a CPU cooling guide available as well.
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rush21hit Look at the voltage setting on those world records. Lots of LN2 involved here.Reply
Speaking as a former user of Q6600 @3.0 (Corsair Hydro series were non-existent back then) and i7 920 @2.8. Small OC, I know. Since I want my motherboard not get fried.
Motherboard gets the most hammering in OC. Even the best of the best sometimes failed. Those capacitors can only hold so much. I just want to ensure it also last. Heck, even in normal use, motherboard tends to fail long before any other parts does. -
Calculatron Ever since the articles on the "E" series of the FX-line-up, I've tried to take efficiency into account. I run a mild overclock of 4.0ghz with just under 1.2V on my FX-8320. I can achieve a 4.7ghz overclock, but I just don't think that the performance gains are worth all the extra heat and stress on the components.Reply -
Nuckles_56 There's a typo in the table of record speeds for the CPUs and the respective voltages, as there is no way that the i7 860 got to that speed at 1.152VReply -
SinxarKnights 18275176 said:There's a typo in the table of record speeds for the CPUs and the respective voltages, as there is no way that the i7 860 got to that speed at 1.152V
http://valid.x86.fr/xuxjnn look for yourself. I suspect there was an error reading the voltage but I do not know, CPU-Z calls it valid though. -
TexelTechnologies Its not that complicated but then again I am always surprised by how dumb people are.Reply -
Murdock4321 Overclocking used to be pretty complicated and take some trial and error. With all these new processors and new bios', its really pretty easy. I'm still rocking an i7 930 @ 2.85ghz which is rock solid and has lasted me since 2010Reply -
jtd871 How about an underclocking/undervolting guide for those that want efficiency rather than performance?Reply -
anbello262 Well, isn't the procedure exactly the same, just lowering mult and volt instead of rising it? The stability concern (freq/volts) and the iterative methodology is the same, right?Reply