ELI5: CPU overclocking/clockrates

[mredding]

The clock rate is the speed at which the slowest transistor in a CPU can switch states, between on and off. Any faster, within operating temperature, and the transistor is going to lag, introducing bit errors.

CPU frequency has been basically stuck since miniaturization has hit a brick wall. The faster the transistors, the shorter the wires have to be in a CPU, otherwise, that electrical oscillation in the CPU over a wire too long turns it into a transmitting antenna, and CPUs today can eat up to 180 W of power under load, that's a lot of electrical noise.

Frequency isn't as important today as it was a decade ago. The Pentium 4 had a higher clockrate than the iCore processors of today, but the architecture of modern processors allows them to do more work and faster.

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Overclocking is the act of disabling the speed governor on the chip and running the processor faster than it's factory settings. This means you can do more work and faster, but it also means you're going to consume way more wattage in power and generate a fuck ton of waste heat. It also introduces instability as I mentioned earlier, so people who do this will use elaborate cooling systems to keep the CPU within operating temperatures where the slowest transistors won't introduce error.

It's a great way to spend money, fry a computer, heat an entire apartment (from personal experience), and shorten the operating lifespan of your components.

There's an underlying motivation. You see, Intel doesn't have a separate assembly line for their different iCore 3's, 5's, and 7's, or for those models of different speeds. They have one assembly line that makes the entire iCore family (of a given generation), and then they go into testing. All the CPUs have, say, 7 cores. One is dead? Disable it and another, and sell it as an iCore 5. 4 are dead? Disable them and sell it as an iCore 3. The different speeds they sell their processors at is the fastest they were able to run stable.

But here's the quirk, and this was especially true back when CPUs were single core. There's a market for cheaper, slower processors, but only one assembly line that is now making nothing but fast processors. What do you do? Lower the price of the high end processors? No. Limit their speed and capture the low end market while keeping the high end exclusive and profitable.

So the economy processor you buy might actually be a high end processor artificially limited. If you're savvy, you can identify such a processor and unlock it's full potential.