Re: [Openbts-discuss] OpenBTS with Raspberry Pi

[Thomas T. <to...@ts...>]

On Sun, Feb 17, 2013 at 6:59 PM, David Burgess <da...@ra...> wrote:
> We have managed to (barely) run a combination 5 beacon plus 1 TCH/F on a 500
> MHz Gumstix Overo. So I would expect that you see better performance. Not a
> lot better, but better.

The Overo (Cortex-A8) has a NEON unit and horribly slow
(non-pipelined) scalar floating point unit. In other words, it's an
absolute mess for the compiler. But, it's a modern, capable processor
and improvements from SIMD optimization can be huge; 10x speedups are
not unheard of.

On the other hand, the ARMv6 based processor on the Pi is from a past
generation. Some code changes are possible (the divide on the sinc
filter is brutal), but without a true floating point vector unit, it's
just not well suited for signal processing. There's a case here for
fixed point, but that's a painful route to go down...

  Thomas