Re: [mpg123-devel] fixed point decoders

[Taihei M. <tm...@ma...>]

Now I've introduced i386 asm optimization and faster code (used when -- 
enable-int-quality is not specified) for the fixed-point decoder. On  
Core2 the generic decoder is still faster, but on P4 the i387_nofpu  
decoder is as fast as the generic one, and on K8 it is faster. It  
looks like a reasonable performance at least on x86 CPUs.

On 2009/06/01, at 23:59, Thomas Orgis wrote:

> It is clocking up for the test over 17 seconds. And even if it  
> didn't, its low-clock mode is 800MHz.
> Even for that I would expect more than half the performance of an  
> old K7 core at less than doubled clock. Tempted to pull out the  
> Alpha EV67 again, to ask it about it's opinion on the performance of  
> old designs;-)
> Somehow I would not be too surprised if the 667MHz EV67 punts the  
> Core2 at 800MHz.
> But, well, this Core2 U7600 seems to be different enough from your  
> average desktop Core2.

Hm, then a mystery... Thinking that the bottleneck of our decoder on  
Core2 is the memory access, maybe smaller (2MB) L2 cache and slower  
(533MHz) FSB have a huge negative impact on the performance.

Thanks,
Taihei Monma