[Interest] Benchmarking machine cpu power

[Sean Harmer]

On Saturday 26 April 2014 11:24:52 maitai at virtual-winds.org wrote:
> Hello,
> 
> I have an application which can be very cpu-intensive, depending on some
> options that play on the precision of computation (you can't expect the
> same precision in the same time on an Android phone or a multi-core
> latest cpu generation desktop).
> 
> Ideally, I would like the application to tune automatically these
> options based on the ranking of the machine cpu-wise, let's say "slow",
> "normal", "fast".
> 
> I will probably write my own small cpuTest routine, but I was wondering
> if there is something in Qt that could return such a benchmarking
> result?

How about allocating a time budget of x milliseconds then timing how long your 
calculations take for precision = n. If it's too slow, reduce n. If it has 
time to spare increase n. QElapsedTimer can help here.

If your algorithm can be parallelised then you may want to consider using >1 
worker thread to distribute the work.

For such tight computations also check your data layout to minimise cache 
misses. This can make a world of difference.

Cheers,

Sean

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