this situation seems to be and on my system:
Celeron 800Mhz, 128 MB RAM, 20 GB 7200RPM HDD :(

Symka.

> Heres the situation
> K6-2/300MHz, 64MB RAM, NetBSD 1.5.1., 2 physical drives both with
>softdeps
>
> While trying to untar pkgsrc.tgz on a un-loaded system (about 20megs of
>RAM used, no swap space used) it's abysmall slow. Disk writes top out at
>about 200KB/second. I did not notice this when the same box was running
>1.5 (and I did untar those files to upgrade to 1.5.1) and it can do the
>reverse process (i.e. tar up the pkgsrc directory) at full speed. RAM
>never gets filled up though, and no swap space is ever used on disk. It's
>odd too, because it seems to go at full speed for about 80 files then get
>really slow.
>
> I've checked when I can, I've tried running the priorities -5 nice,
>I've tried gunziping them first (which is fast) all to no avail.
>
> These same tar files untar fast on another box.
>
>  Any suggestions?
>
> itai at replic d0t net
>
>