[Beowulf] Power calculations , double precision, ECC and power of APU's

Mark Hahn hahn at mcmaster.ca
Mon Mar 18 12:04:34 PDT 2013


> flame-wars?  The people in HPC who care about SP gflops are those who
> understand the mathematics in their algorithms and don't want to waste
> very precious memory bandwidth by unnecessarily promoting their

I'm not disagreeing, but wonder if you'd mind talking about SP-friendly 
algorithms a bit.  I can see it in principle, but always come up short
when thinking about, eg simulation-type modeling with such low-precision
numbers.  does someone really comb through all the calculations, looking 
for iffy stuff?  (iffy stuff can be pretty subtle - ordering 
and theoretically equivalent substitutions.  maybe there are compiler-based
tools that perform this sort of analysis automatically?)

your mention of precious bandwidth is actually relevant to one of the 
earlier threads - that there is an upcoming opportunity for cpu vendors
to integrate decent (much bigger than cache) amounts of wide storage
within the package, using 2.5d integration.  if there were enough fast
in-package ram, it would presumably not be worthwhile to drive any 
off-package ram - any speculation on that threshold?

regards, mark hahn.


More information about the Beowulf mailing list