CPU Stability Testers-summary

[Gene Huh]

Many thanks to those who replied to my query for CPU Stability 
testers.  What follows is a summary of what I found from answers here 
(thanks, sandor!) and elsewhere on the web.

I had originally posted the question because I had overclocked a 
275MHz G3 to 300MHz and wanted to be sure that there were no cryptic 
errors as a result of overclocking.  There seem to be a fair number 
of freeware offerings on the Wintel side, but few free apps for the 
Mac.  Since the MicroMat offerings (TechTool Deluxe and TechTool Pro) 
are not freeware, I have not considered them here.

For example, the Windows freeware program 'prime95' calculates large 
primes.  It has a 'torture test' mode that is very sensitive to CPU 
stability (one little error and it registers a fatal error and 
quits).  Very useful for measuring overclocking stability, as you 
might imagine.  Even the prime95 author acknowledges the utility of 
this program for CPU stability.

The closest Mac equivalents to prime95 appears to be GLucas or Mlucas.

<http://glucas.sourceforge.net/>
<http://gravity.psu.edu/~khanna/hpc.html>
<http://www.mersenne.org/freesoft.htm>

Of these two, Glucas was the easiest to run (almost configuration free).

After downloading the OS X version, the built-in test can be invoked 
by entering the following command in Terminal (after you're in the 
Glucas subdirectory):

./Glucas -s all

This runs all 31 Glucas selftests.  Multiple instances of this 
program can be run in multiple Terminal windows, effectively 
constituting an extended selfttest.  Alternatively, you can run a 
shell script containing several repeats of the above command.   I did 
not find a OS9 equivalent to this program.

Another good test of the integer units on the CPU is the rc5-72 
client (available on www.distributed.net; thanks, sandor ferenczy):

The OS X version (called 'dnetc') is a command-line application that 
you can run via the Terminal application.

<http://distributed.net/download/clients.html>

In Mac OS 9, the client has a test mode built-in (invoked by command-T).

In Mac OS X, the built-in test can be invoked by typing

./dnetc -test

while in Terminal.  Make sure you're in the dnetc-containing 
subdirectory first.   You can do a extended test by running multiple 
instances (as for Glucas above).

Although the above is a good test of the integer execution units, I'm 
not sure that it makes use of (and thus tests) the floating point 
units on the CPU (like Glucas does).

I do not know whether either of the above programs test Altivec components.

Best Regards,
Gene