I’m confused. I did some research online, and learned that cpu’s can essentially double has a hotplate, because 99-100% of electricity consumed is turned into heat. how? doesn’t the cpu use energy to make calcuations and render things? I’m real confused.
In: 1619
Your computer is, fundamentally, a bunch of switches that switch states by either having a lot of current flowing through them or very little current flowing through them. Whether there is a lot or a little current are the 1’s and 0’s through which computers encode information.
The thing about having a bunch of current flowing through your chips and the wires connecting them is that it creates electrical resistance. In terms of its impact, electrical resistance is kind of like friction. When I push something along my floor, Some of the energy from me pushing the thing gets lost due to friction and the result is that that energy winds up in the thing I’m pushing and the floor as heat.
So, basically, to constantly have current running through your computer electrical resistance is inevitable and heat is the byproduct.
Making those calculations, makes heat. It’s not using energy to move physical gears, or producing light; the only form energy is being changed into is heat through electrical resistance.
Where else would the energy go?
“There are six types of potential energy: mechanical energy, electrical energy, chemical energy, radiant energy, nuclear energy, and thermal energy.” – [source](https://justenergy.com/blog/potential-and-kinetic-energy-explained/#:~:text=There%20are%20six%20types%20of,nuclear%20energy%2C%20and%20thermal%20energy.)
If the electrical energy in the CPU doesn’t become any of the others, it becomes heat energy. Nothing is moving against gravity, so it’s not mechanical potential energy. No chemical reactions are happening, so it’s not chemical energy. It doesn’t give off significant amounts of light (everything emits some IR, but not much here), so not much radiant energy. No nuclear reactions, so not nuclear energy. And it’s not kinetic energy bendy nothing is moving outside the CPU. All that’s left is thermal energy!
Energy can’t be created or destroyed.
If your cpu takes 100w of electrical power, it will output 100w of thermal power.
Everything will eventually become heat. Light from your lightbulb creates heat… Car drives down the road only to convert energy to heat (brakes, air friction…)
Calculations and information are just arrangements of electrons. Your CPU is constantly moving electrons around and checking where they are. Wires have resistance, transistors and capacitors leak. Eventually (pretty quickly) it all becomes resistive heat and you have to put more energy in to keep it going. A lot of research goes into trying to get more calculations for less heat, especially in battery powered devices like phones.
All energy becomes heat eventually. It’s basic thermodynamics. It’s just a question of how, and whether the energy can do something useful in the process. A car also converts all of its fuel energy into heat, most of it in the engine block that is dissipated in the radiator, some in the tires, and the kinetic energy eventually becomes heat in the brakes.
Energy cannot be destroyed, only converted. Electricity can be converted to mechanical energy, light energy, or some other form of energy. The most common is to heat energy.
Nearly everything that runs on electricity ends up turning it into heat eventually. The CPU just does it in a concentrated location, rather than say an electric car that spreads the heat out to the air and pavement as it drives. Thus, the CPU gets hot and need help spreading that heat out to the air.
Energy doesn’t disappear, it is only converted to different types of energy. When we talk about energy loss in electronics, what we mean is that some amount of energy was converted to heat. Heat is the most fundamental form of energy. All energy “wants” to become heat. If what we _want_ is heat, then now we’ve changed the equation and what was once “lost” is instead a useful output.
CPU’s are very good at doing work with the electricity input until it escapes as heat
I wonder if you’re confusing two different concepts.
[Conservation of Energy](https://en.wikipedia.org/wiki/Conservation_of_energy): “Energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another”
and
The [quantum theory](https://en.wikipedia.org/wiki/No-hiding_theorem): “conservation of quantum information should mean that information cannot be created nor destroyed.”
A CPU doesn’t convert energy into information, it simply performs calculations that ultimately derive from combining or splitting rises and falls in electrical output (which are transformed, simply stated, into binary logic gates.) The electrical energy never _becomes_ information, it only _represents_ information. Paint on a canvas remains paint, even if we _interpret_ that paint as information. CPU electricity mostly becomes heat.
The calculations and rendering things is just the computer moving things around, which generates a little heat.
The computer does convert energy into other forms of energy. It makes noise, some of this energy from the sound dissipates into heat in your home, some may escape outside.
It generates light and sends out Wi-Fi radio waves. Some of this may escape your home, but most quickly and nearby dissipates into heat.
The calculations are done by turning electricity into heat in various different ways.
Or to put it another way, an electric hotplate has exactly one way of turning electricity into heat. A CPU has many ways to turn electricity into heat.
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