[flac-dev] Performance checks

[Martijn van Beurden]

On 28-05-13 20:09, Janne Hyvärinen wrote:
> On Windows the 32-bit NASM enabled compiles are always fastest. If you 
> can run 32-bit code on your Linux box you should compile with assembly 
> optimizations.

That depends on the way you define speed. For decoding this doesn't seem 
to be true. I reran my tests, it took a little longer because I couldn't 
believe the results I got. However, they are perfectly reproducible (on 
my system at least), so I guess I'll have to believe them.

In the linked PDFs is first a test with the average of 5 CDs and second 
the graph of only one of those 5. It is clearly visible that the 'speed 
ranking' for each compression setting match very closely, so the 
accuracy is probably pretty high. I did this comparison on Kubuntu 12.10 
64-bit.

http://www.icer.nl/misc_stuff/All tracks.pdf
http://www.icer.nl/misc_stuff/Coldplay - Parachutes.pdf

I was surprised to see that the Windows compile on wine actually 
outperformed the native Linux one. Probably GCC 4.6 optimized a little 
better or something very weird is going on in wine, I don't know. The 
assembly optimizations work very well on encoding, but actually slow 
things down when decoding. The difference is not very large however.

Anyway, I think I'm convinced now that my lossless codec comparison was 
valid and I can keep running codecs through wine. I should probably run 
all of them through wine just for the sake of clarity.