[Beowulf] Opinions of Hyper-threading?
landman at scalableinformatics.com
Tue Feb 26 16:42:05 EST 2008
Bruno Coutinho wrote:
> Yes, and more than an out of order processor. A out of order processor,
> can reorder the instructions whenever a hazard occurs. A in order
> processor, on the other hand, has to wait. With SMT, it can switch to
> another thread.
> And today memory access can stall up to hundreds of cycles, so any
> processor can hide this latency by switching to another thread.
My gosh ... we have re-invented the Tera MTA. ...
> But the you have to make sure the processor has enough cache and memory
> bandwidth to handle the increased memory traffic (like Sun Niagara).
The problem with many (cores|threads) is that memory bandwidth wall. A
fixed size (B) pipe to memory, with N requesters on that pipe ...
Joseph Landman, Ph.D
Founder and CEO
Scalable Informatics LLC,
email: landman at scalableinformatics.com
web : http://www.scalableinformatics.com
phone: +1 734 786 8423
fax : +1 866 888 3112
cell : +1 734 612 4615
Beowulf mailing list, Beowulf at beowulf.org
To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
More information about the Beowulf