SUN-4 FPU

[jan at eik.ii.uib.no]

In v7n114 Ruth Milner writes that all Sun-4 series machines come installed
with the FPU. This is -unfortunately- dead wrong. The Sun-4/2x0 is
delivered with the FPU, for the Sun-4/110 it is an option. (Here in Norway
it costs an additional $3000.)

She is right when she states that it is not necessary to configure it into
the kernel. Also during boot the system prints out a line on the console,
stating whether an FPU was found or not. (I haven't checked if it has a
program comparable to the 'mc68881version', but I don't think so.)

It is our experience that the Sun-4/110 is worthless for floating-point
intensive applications *without* the FPU. (In fact it is embarrassingly
bad, it cannot even compare with a Sun-2! If anybody has different
experiences we sure would like to hear about it.)

So if your applications are floating-point intensive, get the FPU. If you
run AI-applications start saving up money for memory-upgrades. (LISP works
on 8MB, forget about using SPE with less than 16MB.)

If anybody thought this is a FLAME, it isn't *really*. It just points out
that a nice machine could have been even nicer ... (And it would have been
nice to have known about the floating-point performance before we bougth
the machines.)


Jan Berger Henriksen
Institute of Informatics		E-mail:	jan at eik.ii.uib.no
University of Bergen				jan%eik.ii.uib.no at tor.nta.no
Allegt. 55
N - 5007 Bergen,
Norway