[Beowulf] itanium vs. x86-64

[kyron at neuralbs.com]

> kyron at neuralbs.com wrote:
>>>> Next caliper allows to get a lot of diagnostics from the cpu (also
>>>> because
>>>> ia64 supports all that while x86-64 does not AFAICT) like number of
>>>> bubbles
>>>> in the pipeline, L2-cache misses, clock-cycles per line of C-code etc.
>>> these are just the performance-counting MSR's, which are available
>>> on Opterons as well as Xeons too.
>>
>> Even back to the PIII processors (and more?). Check out PAPI
>> (http://icl.cs.utk.edu/papi/) for more details but, as an example, here
>> is
>> the output from an old cluster node:
>
> Oops. Well actually great to hear. Which profilers can benefit from all
> this info?

This monster suite (free!):
http://www.cs.uoregon.edu/research/tau/docs.php
Which I have been pushing around for a while and it's quite impressive
IMHO. Weird thing is I seem to be the only one interested in profiling and
metrics and all that gunk around here. Guess that will change now that it
is actually possible to _measure_ the FLOPS your application _truely_
consumes thanks to these counters (I mean, for us laymans that never had
access to such cool hardware :P )

>
> toon
>
Eric