Quick, Standard Measurement for CPU Power? 31
captnitro asks: "A particular research project I'm developing right now needs to compare 'potential' (idle/none) and 'load' for various hardware capabilities, and quickly -- maybe up to a several times every minute. For disk space, for RAM, it's relatively easy -- find what's used and what's not and report the ratio. For CPU, I have plenty of time to test 'potential' when the app starts. But for testing CPU load, I need a standard 'ruler' that will be able to compare across varying platforms and processors (e.g., x86, PowerPC, embedded, single and multi-proc) -- so for example, idle percentage won't work. At the same time, I don't have the ability to time 'openssl speed' every 25 seconds without bringing the system to a halt. I'm willing to sacrifice precision of the measurement for generalization of the unit -- that is, the operations that this test is for would be primarily mathematical and not say, text sorts -- but I'd prefer a generic, quick test of the current processor load rather than an average of 25 different tests. Regardless of hardware, the OS distribution is mostly *nix-based -- NetBSD, Linux, and even Mac OS X. Wild ideas are perfectly acceptable -- any thoughts?"
Bogomips (Score:2, Funny)
Potential CPU available ??? (Score:5, Informative)
I am not even sure there is a way of measuring what you want. There are so many variables (Disk I/O, memory bandwidth, etc.) that you can't get a reasonable measurement of how much CPU is left over to do useful work for your process.
The other thing is that many things can take down a CPU as well - a huge burst of network traffic can take an "idle" CPU and peg it at 100% in kernal usage.
Your best bet would probably be to hook into the various schedulers and get deep knowledge of what is really going on - pain in the butt, but doable
Potential CPU available vs benchmarked CPU (Score:2)
The easiest way to get a % is from something like top - but you can definitely do better, especially by successfully taking into account priority. You definitely want to find a way to _access_ information the scheduler already has, not make little minibenchmarks.
But you still have the problem of 100% of a PII vs 100% of a G5. This is a principally insoluble problem that varies based on your application's use of int, flop, registers, L1, L2,
How about (Score:3, Insightful)
Or!
Watts of thermal power on the die surface!
Re:go ahead and use idle percentages (Score:3, Interesting)
What are those priorities, Interupt handling, high priority applications, ???
What this person might be considering is some kind of batch job scheduling environment - where you want to schedule an incoming job on the system with the greatest current capacity to process it. ie. using free re
Re:go ahead and use idle percentages (Score:1)
Re:'nice 19' to the rescue (Score:2)
Re:'nice 19' to the rescue (Score:2)
At least that was the case last time I tested with the linux 2.4 kernal.
SPEC (Score:4, Informative)
Say hello to SPEC [spec.org]. This is exactly what the organization was formed for. Take a look at their CPU benchmarks. I know you're looking for more of a snapshot, and less of a benchmark - but I would think SPEC is a good place to start.
Probably not SPEC, maybe javascript or flash.... (Score:1)
Then again, it's possible that the application could be used to measure the speed of web clients. In that case, a flash or javascript loop with whirling icons could do the trick, but it would take
Amps (Score:1)
openssl speed (Score:2)
Re:openssl speed (Score:2)
Yeah, that was more or less what I was thinking too, except I'd be tempted to use CPU temperature instead of power consumption, just because most hardware platforms already incorporate heat sensors for CPU's, and I don't know of any commodity hardware which will tell you how many watts your CPU is drawing.
It would be imperfect, because other things can influence CPU temperature -- some CPU's have variable-speed fans (especially on laptops), and other factors can cause temperatures to rise inside the case
Em Eye Ess (Score:2)
Two Mississippi.
Three Mississippi.
Weigh energy consumption also (Score:4, Insightful)
Easy - CPU Speeds (Score:4, Funny)
Fast
Freakin Fast
Holy Shit
Dude you r0x0r
OMFG
Oh, just so you know, you should always buy at the Holy Shit level. If you buy OMFG you pay too much and you will soon regret buying anything less than Freakin Fast. But Holy Shit and you will be happy for a couple to three years without paying too much.
Alas, not quick... (Score:4, Informative)
The paper you're looking for is Wong, Brian, "Comparing MVS and UNIX Workload Characteristics" Int. CMG Conference, 1998, in which (if memory serves) he looks at the comparability of MVS and Unix programs, and derives a series of comparisons which very approximately correlate with TP performance in a benchmark like TPC.
A paper that's available to CMG [cmg.org] members is his Developing a General-Purpose OLTP Sizing Tool [cmg.org], which builds on the subject.
If you have any good, representative test that load a whole system, then in my opinion, you have a good predictor of average performance. (Tautology, eh?) If you have such a test, though, people will learn how to get the best posible numbers from it. Average together all the various X MHz Pentium III TPC-C results, don't trust any single one (:-))
--dave
quicky (Score:1)
Flops (Score:1)
Consider:
http://en.wikipedia.org/wiki/Flops [wikipedia.org]
http://en.wikipedia.org/wiki/Million_instructions_ per_second [wikipedia.org]
Re:Flops (Score:3, Funny)
Engineers now build marketers?
Random idea.. (Score:1, Interesting)
2) Using #1, calculate the current draw of CPU (perhaps use a separate dedicated power supply for the CPU and/or mobo) and therefore the current CPU utilization.
You might need to address temperature in there too. Or *only* use temperature rather than current (for instance temperature difference between the outs
Password Cracking (Score:2)
http://the1.no-ip.com/~the1/johnbench.txt [no-ip.com]
You can download the john the ripper source code here:
http://www.openwall.com//john/ [openwall.com]
and then build it and run your own tests.
Re:Password Cracking (Score:2)
http://www.teamquest.com/resources/gunther/ldavg1. shtml [teamquest.com]
Hmm... (Score:2)