[Interest] Benchmarking machine cpu power

[Sean Harmer]

On Sunday 27 April 2014 12:51:50 maitai at virtual-winds.org wrote:
> Thanks for your reply,
> 
> That was my intend to write such a small routine that will sample the
> CPU and automatically tune the various options in order to achieve
> something reasonable for the user and machine.
> 
> May be a bit off topic, but what do you mean exactly by "minimising
> cache misses"? There is no disk access during calculation phase (which
> is multithreaded).

I meant CPU caches misses. When iterating over data try to make sure it is 
contiguous in memory rather than dispersed all over the place. 

One example from typical 3D scenegraphs is updating world transformation 
matrices and bounding volumes. Ensuring that the matrix data for all nodes is 
contiguous (rather than the Nodes and all their other data being contiguous or 
scattered over memory) means that when iterating we will have fewer cache 
misses and therefore that your CPU will spend more time operating on your data 
rather than waiting for it to be transferred from main memory.

This interactive demo gives you a good feel for relative access times of 
various cache levels and main memory.

http://www.overbyte.com.au/misc/Lesson3/CacheFun.html

As always, benchmark :)

Have fun,

Sean

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Dr Sean Harmer | sean.harmer at kdab.com | Managing Director UK
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