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