Some optimization opportunities

[Jordi]

> > Calling gettimeofday this often seems a little strange to me and
> > certainly an important part of the 35 ms here is wasted due to system
> > call overhead.
>
>   well, here you're assuming that *nothing* is being done between
> gettimeofday() calls. and as Maks pointed, strace *really* slows things a
> lot.

gettimeofday() is related to events, for instance mouse moves. It's part of Qt 
and i'll say it's very optimized.

Regards
Jordi Polo