-------------- Original message -------------- From: "Peter St. John" <[EMAIL PROTECTED]>
DLP? Wiki has entries for Indtruction Level Parallelism and Thread LP (alsom Memory LP) but not DLP? Hey Peter, That would be "data level parallelism". So, ILP is very low level parallelism which works on somewhat locally scoped instructions that are independent in a super-scalar, fanned-out parallel way on a "wide" processor. TLP refers to a slightly higher level of parallelism that is instruction dominated/oriented and is associated with independent program blocks or loop interations (can be within or between programs or subroutines), and DLP refers to data dominant parallelism usually associated with looping structures that could vectorize or, in other words, allow a compiler to stimulate, with a small number of instructions, a large pipeline (and/or parallel stream [think GPUs here]) of independent data operations in the CPU for which the total instruction latency is trivially small in theory (i.e. when you have a vector instruction set). In one sense, the low level parallelism (and structural hazard performance limitations) of any program can be defined by a sort of aspect ratio that is ILP x DLP x TLP and every code/kernel has its own dimensionality and volume. A major question for performance and processor design is also, which kind of latency dominates --instruction latency or data latency--in limiting a code's performance to something less than register-to-register optimal. Generally, in HPC data latency is dominant and the Enterprise world is instruction latency dominates. But now I am probably rambling, and telling you something that you already know. Regards, rbw -- "Making predictions is hard, especially about the future." Niels Bohr -- Richard Walsh Thrashing River Consulting-- 5605 Alameda St. Shoreview, MN 55126 Phone #: 612-382-4620
--- Begin Message ---_______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
--- End Message ---
_______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
