donlee_68k@icompute.com wrote:

>I just recently acquired a Quadra 840AV for $35.  (I consider it a steal ;-> )

>In theory, it should be faster than my Quadra 610, because it has
>an 80 Mhz CPU w/ 40 Mhz bus and the Q610 has a 40 Mhz CPU with a 25 Mhz bus.
>Depending on who you ask, the CPU rates on both may be half that, but in
>any case, the 840 AV should be faster.

[...]

>The upshot is that while this program is running, the real-time/wall-time
>clock on the Q840 slows down to about one tenth of its proper speed.

>Two questions:

>	1. Is there something broken on the Q840 that would slow down
>	the CPU and/or I/O?  any options that I should be setting?

>	2. Why does the clock behave so badly?  If this is a known
>	problem in 1.4.1, will it be fixed in the (soon to be releaed??)
>	1.4.2?

There's some mention in the install notes that the interrupt structure
of the Mac somehow interferes with the time-of-day clock, and that running
I/O-bound processes will cause the clock to lose several minutes each
hour.

Apparently there's something inherent in the way that NetBSD interacts with
the Mac hardware to cause this, but it's probably fixable; Apple A/UX did
not exhibit this problem.  As for how easy such a fix will be can only be
ascertained by the NetBSD kernel architects, though.