When it comes to the ‘work energy’ of a computer, the answer is quite different.
What is work energy?
According to a 2012 report by the US government, it is the time required for the process of processing information and data to occur.
So what does that mean for you?
‘The term ‘work’ is often used to refer to the process that is performed, but it’s not always clear how work actually works, or how it relates to computer programs,’ says Dr Juliane Witte, a lecturer in computer science at the University of Warwick.
‘What we really want to know is how much energy a computer uses, and if the computer can do it at a reasonably low cost.’
We can do this by looking at the energy required to process a large amount of data.’
Dr Witte says there are three major types of energy a CPU needs to process data, but that they are not all that different.
These are power, heat and noise.
‘The power of a CPU is the amount of power it needs to operate at a given frequency, such as a desktop processor,’ Dr Wite says.
‘A CPU that is running at a very high frequency will use a lot of power, because that’s how the CPU works.’
But a CPU that’s running at much lower frequencies, for example a laptop, will only use a small amount of energy, because its processing is done in parallel, and the processor is a lot more efficient.’
The other two types of work energy are heat and vibration.
Heat is the energy the CPU needs when it’s working on data.
For example, if you are working on a spreadsheet, your CPU is going to use heat to perform the calculations.
This can take up to 30% of the processor’s power.
‘Vibration is the same energy, but you can’t just turn the CPU off and go back to the way it was, because it’ll take energy to do that,’ Dr. Witte explains.
‘It’s the amount that the processor uses when it does its work.
If you’re working with images on a computer screen, that’s a lot less energy because you can control what the computer sees by turning off the CPU.’
If you work with data, the CPU will have to work harder to do the same calculations.
‘This is the kind of work that the brain does, so you can see how much power a CPU requires to do some simple calculations,’ Dr Chris Hallett, an engineering professor at the Australian National University, says.
But what happens when you work in virtual environments?
Virtual environments can also take up a lot longer to process and process data.
A virtual computer could use up to 20% of your processor’s energy, while working in a physical computer, it will require only 10% of its energy.
‘You could also work with more complex data, such like text or images, where you could get an approximation of how much data the CPU can process at a time,’ Dr Halleitt says.
Dr Wittle says that in these cases, the energy savings of a microprocessor are more likely to be measured in terms of the number of operations performed per second.
The ‘work power’ of the computer is also dependent on the system you are using.
‘One of the big things that people often get confused about is whether a microcontroller can run on a PC, or whether a CPU can run a PC,’ Dr Lacey says.
She explains that while the amount the processor requires for each operation is the ‘power of a processor’, it is not the ‘working power’ because that is different for each application.
‘For example, when you use a PC to process images, your processor will need a lot fewer operations to process those images than if you use the CPU to process text, because the CPU doesn’t need to work as hard to do those operations,’ she says.
If your microcontroller is a PC then the energy used by your processor is proportional to the speed of the PC.
‘But what happens if you’re doing some really complex calculations on a microchip?
What about the time it takes for the CPU and GPU to work together?’
Dr Wisse says it is important to remember that the work energy of a PC can be reduced if the processor or GPU is not running at the same time.
‘When you’re talking about an embedded system, for instance, the work that’s required for a computer program to be run is actually proportional to its time,’ she explains.
The energy savings associated with the microprocessor and the GPU can be much larger, because in order for the processor to run at a high speed it needs more power than a GPU does.
Dr Hulett says this type of power use can be the difference between being able to get to the top of a mountain or being unable to do so.
If a computer has