Here's some wall clock times on a dual Opteron 240 system running Gentoo
Linux.
64-bit GCC executable: 7:22
32-bit GCC executable: 10:56
32-bit GCC+nasm executable: 6:50
As you can see compiling in 64-bit mode makes a very appreciable difference.
A straight C 64-bit executable is almost as fast as the assembly optimized
32-bit version.
The input file was a PCM rip of the album 23am by Rober Miles(total length
about 61:02). The lame command line consisted of just the input file name,
i.e. defaulting to 128bit CBR output.
All binaries were compiled with GCC. Version 3.3.2 for the first 2 and some
earlier version for the assembler version. The assembler version also
probably had slightly more aggresive optimization flags.
I've been working on converting the ia32 assembly files to amd64 assembly.
I've converted and tested the some of the files using the yasm assembler.
So far I have not tested the converted files as part of lame as I'm not yet
familiar with how the automake/autoconf stuff works. I come from a
predominately Windows programming background :) I'll probably figure out
what I need to know sometime in the next few weeks but if anyone has any
pointers they'd be appreciated.
John Stewart
P.S. Complete output from the lame executables is below.
64 bit executable:
LAME version 3.95 (http://www.mp3dev.org/)
Using polyphase lowpass filter, transition band: 17249 Hz - 17782 Hz
Encoding 23am.wav to 23am.wav.mp3
Encoding as 44.1 kHz 128 kbps j-stereo MPEG-1 Layer III (11x) qval=3
Frame | CPU time/estim | REAL time/estim | play/CPU | ETA
140217/140219(100%)| 7:22/ 7:22| 7:35/ 7:35| 8.2809x| 0:00
average: 128.0 kbps LR: 4648 (3.315%) MS: 135572 (96.69%)
Writing LAME Tag...done
ReplayGain: -5.5dB
32 bit executable:
LAME version 3.95 (http://www.mp3dev.org/)
Using polyphase lowpass filter, transition band: 17249 Hz - 17782 Hz
Encoding 23am.wav to 23am.wav.mp3
Encoding as 44.1 kHz 128 kbps j-stereo MPEG-1 Layer III (11x) qval=3
Frame | CPU time/estim | REAL time/estim | play/CPU | ETA
140217/140219(100%)| 10:47/ 10:47| 10:56/ 10:56| 5.6544x| 0:00
average: 128.0 kbps LR: 4648 (3.315%) MS: 135572 (96.69%)
Writing LAME Tag...done
ReplayGain: -5.5dB
32 bit mmx executable:
LAME version 3.95 MMX (http://www.mp3dev.org/)
CPU features: MMX (ASM used), 3DNow! (ASM used), SSE, SSE2
Using polyphase lowpass filter, transition band: 17249 Hz - 17782 Hz
Encoding 23am.wav to 23am.wav.mp3
Encoding as 44.1 kHz 128 kbps j-stereo MPEG-1 Layer III (11x) qval=3
Frame | CPU time/estim | REAL time/estim | play/CPU | ETA
140217/140219(100%)| 6:37/ 6:37| 6:50/ 6:50| 9.2033x| 0:00
average: 128.0 kbps LR: 4648 (3.315%) MS: 135572 (96.69%)
Writing LAME Tag...done
ReplayGain: -5.5dB
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