I work in the software industry. At my company, we're trying to find an English term for the unit of cost for a computer process work, which consumes CPU, Memory, disk-usage, etc.

Our PM has come up with the term Computing Cycles. I tend to think it's incorrect English. I found an article which uses the term Compute Cycles.

Which term describes best that unit of cost? "Computing cycles," "compute cycles" or maybe something else?

An example of using the terms:

  • image resizing algorithm for 100 big pictures costs 150 Compute Cycles
  • image resizing algorithm for 100 big pictures costs 150 Computing Cycles

3 Answers 3


I think instruction cycle is the most commonly used word. I think I have heard computing cycle as well, but I'm not sure. Wikipedia and Dictionary.com redirect the latter to the former; that is evidence that computing cycle is in use as well.

  • @Ceberus Wikipedia redirect Computing Cycle to Instruction Cycle, but it doesn't mean Computing Cycle is in use. Apr 13, 2011 at 7:40
  • @AsaMesika: I'm not saying it's a generally approved word; just that apparently some people consider it equivalent and use it (if it weren't used at all, there'd be no redirect). Apr 13, 2011 at 11:25

It sounds like what you're looking for is instruction cycles - but that's generally too low level to be useful as paths of execution may diverge, fetch operations may need to go to main memory rather than cache etc.

Generally people don't worry about individual clock/instruction cycles and abstract it away in the form of Big O notation

CPU time is the amount of processing time a program takes which is another metric people use.

  • 3
    I generally agree, except that as someone who works in embedded systems, I really do want to know how many clock cycles an operation will take. If we're going to have a lot of cache misses, recoding the algorithm to avoid them matters a lot!
    – user1579
    Apr 12, 2011 at 12:49
  • 1
    @Rhodi - Yep that's certainly one of the times it does matter! Clock cycles is also a good term as 1 clock cycle doesn't necessarily equal 1 instruction cycle
    – Robb
    Apr 12, 2011 at 13:41
  • Instruction Cycle doesn't take into account Disk usage (I/O). If the algorithm involves several computers with different CPU speed, you may to want to define a unit which encapsulates all possible usage. The main question is: Which is more correct English: Computing Cycles or Compute Cycles? Apr 13, 2011 at 7:39
  • 1
    @Asaf Mesika Given a choice between only those two terms, computing cycles is better English. Because the cycling is ongoing, the verb to compute is conjugated in the present continuous as computing.
    – Uticensis
    Apr 13, 2011 at 9:04
  • @Asaf Mesika - I'd agree with @Billare, Computing Cycles is the way forward.
    – Robb
    Apr 13, 2011 at 9:20

Sometimes new words are welcomed into use when it becomes clear that it's needed. Even though computing cycles isn't a widely used term yet, it might very well be soon.

  • I don't think computer cycles will become widely used, because it has no meaning for most people. People in the computing business already have terms for the things they care about - Processor cycles, Megaflops, Disc / Memory Accesses, etc. But any given computer system always some 'bottleneck' or other, and it's usually pointless improving performance in any other areas. You have to identify the actual limiting factor and work on that. Apr 12, 2011 at 15:25
  • My husband, a software developer, uses the word "computing cycles" (not "computer cycles") to describe what @Asaf Mesika explained in the question.
    – masarah
    Apr 13, 2011 at 7:37
  • And a word/term does not have to be used by "most people" to be considered correct. Most subject areas have certain words that are used within the area.
    – masarah
    Apr 13, 2011 at 7:39
  • 1
    @FumbleFingers If you want to measure overall usage of Processor Cycles, Memory Access and Disk Access as one unit of work, than a new unit named Compute / Computing Cycle can be handy. Apr 13, 2011 at 7:42
  • @Asaf Mesika: There is no such thing as "one unit of work" for a computer. It's as meaningless as talking about "one unit of food". Where you can only "unify" carbs, fats, protein, vitamins, etc., by converting them all to Recommended Daily Allowance percentages. In the case of the PC the only measure that matters is the one that's limiting total throughput most, in the context of the apps it runs. Apr 13, 2011 at 11:23

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