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Why Do Computers Use So Much Energy?
131–140 of 174 posts
Re: Why Do Computers Use So Much Energy?
#132It'd be great if we not only measured software performance, eg the way we measure web servers with requests / sec, but also requests / sec / watt.
Re: Why Do Computers Use So Much Energy?
#133While the article deals with theoretical limits, there are some practical limits. As they are already coming up in other comments might as well list them out: [...] There are several factors contributing to the CPU power consumption; they include dynamic power consumption, short-circuit power consumption, and power loss due to transistor leakage currents: [...] [1] https://en.wikipedia.org/wiki/CPU_power_dissipation…
CMOS especially, which consumes energy in direct proportion to the square of the frequency because a level crossing is a virtual, instantaneous short-circuit across the chip's power rails.
As such, future chip will likely be driven to reversible / adiabatic tech because cryptocurrencies, AI and more are guzzling energy ($$$ and running more circuits) and dissipating more heat that can be sensibly handled in a given unit volume (per-socket thermal characteristics; chilled water plant capacity; forced per-cabinet cooling or submersed in mineral oil).
Re: Why Do Computers Use So Much Energy?
#134What i don't understand is how a phone can be so powerful with so little watt usage. especially compared to a PC
Phones are much less powerful than PCs, but they feel comparably fast because most software developers waste exactly as much performance as they can get away with. The phone app developers are forced to write better, faster code than the PC app developers, just as PC app developers ten years ago were forced to write better code than PC app developers are today.
> Phones are much less powerful than PCs, but they feel comparably fast
I beg to differ.
My Droid Turbo is powered by a 2.7 Ghz quad-core CPU, yet often is incredibly slow. If I want to open Waze and enter and address to navigate to, it's often 10-15 seconds from the time I tap the Waze icon on the launcher until the apps is loaded and the on-screen keyboard has presented itself for typing.
There are significant stutters when I'm trying to scroll while a web page is loading.
Fallout Shelter takes nearly an entire minute to load.
Sometimes, plugging in a USB charger causes the phone to basically become a brick for half a minute or more, as if there are tons of apps deferring processing until I'm on external power.
Overall, it often doesn't feel any more responsive than my original Droid back in 2010, which was only a 550 Mhz single core.
Re: Why Do Computers Use So Much Energy?
#135> Precise estimates vary, but currently about 5 percent of all energy consumption in the U.S. goes just to running computers 30% goes on transport. > the human brain is a computer. This particular computer uses some 10–20 percent of all the calories that a human consumes So society's computer uses 5 percent and our own, evolved over millions of years, uses up to 20. I'm not saying computers can't or shouldn't be made…
>> Computers don't use very much energy compared to almost everything else in the world.
So highly parallel system are closing in on Teraflops per watt, which sounds amazing to me. But I really have no idea if that's high or low power.
Re: Why Do Computers Use So Much Energy?
#136Bitcoin and high end video cards.
Re: Why Do Computers Use So Much Energy?
#137> Precise estimates vary, but currently about 5 percent of all energy consumption in the U.S. goes just to running computers 30% goes on transport. > the human brain is a computer. This particular computer uses some 10–20 percent of all the calories that a human consumes So society's computer uses 5 percent and our own, evolved over millions of years, uses up to 20. I'm not saying computers can't or shouldn't be made…
It would make more sense to compare absolute numbers. A brain uses about 20W. A modern computer has similar consumption, but is many orders of magnitude less powerful.
That's largely because the brain is not clocked synchronously, something like 30% of a modern CPU is lost in clock trees. The brain wakes up the bits it needs on demand almost at a per-gate (neuron) level.
Re: Why Do Computers Use So Much Energy?
#138> Precise estimates vary, but currently about 5 percent of all energy consumption in the U.S. goes just to running computers 30% goes on transport. > the human brain is a computer. This particular computer uses some 10–20 percent of all the calories that a human consumes So society's computer uses 5 percent and our own, evolved over millions of years, uses up to 20. I'm not saying computers can't or shouldn't be made…
My thoughts exactly. When reading the title I thought "They do?" My laptop consumes the equivalent of approximately a single 60w incandescent lightbulb that used to be required just to write on a pad of paper in the dark. It's capable of quite a bit more than that, however. EDIT: Updated power specifications to exact amounts.
I was going to say that you could write just fine by candlelight instead, but it turns out a candle uses about as much energy as that light bulb (based on random internet spot-checks).
Re: Why Do Computers Use So Much Energy?
#139> Precise estimates vary, but currently about 5 percent of all energy consumption in the U.S. goes just to running computers 30% goes on transport. > the human brain is a computer. This particular computer uses some 10–20 percent of all the calories that a human consumes So society's computer uses 5 percent and our own, evolved over millions of years, uses up to 20. I'm not saying computers can't or shouldn't be made…
physicist here. Stop comparing numbers that don't mean the same thing. You're making my eyebrows twitch.
Re: Why Do Computers Use So Much Energy?
#140Earlier quoted context omitted.
A single modern CPU can crunch more numbers in a second than every person living on earth combined. Sure there may be things that it's not capable of, but most things it is capable of, it's usually 8-10 orders of magnitude more efficient at.
The brain still tops every CPU at visual processing, which may be its highest throughput interface.
It’s almost like brains and computers are somehow different.