I noticed a lot of encoders on RareWares (including flac) that are optimized for different processors. What are the advantages and disadvantages of using an optimized encoder verses the encoder that you download from the main development site?

Also, does anyone know where the Pentium-M fits in? Can I run the P4 optimized flac encoder on a laptop with a PM (not P4-M) chip or am I better off sticking to the original?

Generally the optimized versions will run faster than their non-optimized counterparts.

Pentium-M CPUs (Banias or Dotham core) are based on the old Pentium III Tualatin core.

As to the flac encoder binary, it might run... it depends on what exactly "P4" optimizations mean. If it's just SSE2, then that should run on the Banias/Dotham chips as well. Your best bet it just just try. If the binary segfaults, well then it didn't work

You will have to try both. P4 requires some odd optimisations that might slow things down on an older core (like your PIII-M). Your best bet is to download both the Pentium 4 and generic versions and see which is faster.

For FLAC the advantage of an optimised encoder is increased speed. There are no disadvantages (unless your hardware is flaky in which case the optimised version is more likely to not work).

I'm using the P4 optimized flac.exe. It might be faster, but it's not anything that makes me go wow!

you'll only get so much from a mmx/sse-aware compiler. most of the gains probably come from the few hand-written asm routines in libFLAC. there are mmx and sse versions of some functions, but no sse2.

Josh

edit: maybe the small difference is because the official win32 flac binary release is already compiled with mmx support, (but not sse since that requires OS support for it).

:deleted: