Re: Dired C idea

[Gregory Heytings]

> > > > I would like to see some benchmark figures first. For example, I'm 
> > > > not sure that rsync performs better when the target directory does 
> > > > not exist yet, and there's nothing to sync.
> > >
> > > I made some comparison between "cp -pr" and "rsync -pr" on shell 
> > > level. [...] "rsync -pr" is slower than "cp -pr".
> >
> > Yes, nothing can beat cp;
>
> Is cp really bottleneck at all? Isn't it more likely IO that is limiting 
> operation?

cp does (almost) nothing except IO, so indeed IO is the bottleneck. 
rsync does more than IO, so it is slower.

Note however that, as Fabrice just said, you should not compare "cp -pr" 
with "rsync -pr", you should compare "cp -a" with "rsync -a".  After 
"rsync -a SRC DST", another "rsync -a SRC DST" is much, much faster, and 
when DST already contains 50% of the files in SRC, "rsync -a SRC DST" will 
take ~50% of the time of a full copy.