Hi,
Interesting to compare the performance numbers given for the Itanium
running Glucas v2.8c against my Thunderbird running mprime v21.4 :
AFAIK, mprime v21.4 now uses prefetch hints to avoid idle cycles waiting for
new data. Glucas/Itanium (C-plain code) uses a kind of preload, no
Hi again,
I forgot to comment an observation made when writing Glucas for Itanium.
IA64 architecture has a very nice feature: predication. In the DWT used in
most GIMPS clients, the normalization and carry phase has a relevant cost in
terms of performance. There some branches hard to predict
On 20 Oct 2001, at 9:44, Mikus Grinbergs wrote:
Interesting to compare the performance numbers given for the Itanium
running Glucas v2.8c against my Thunderbird running mprime v21.4 :
- At the smallest FFT length, the Itanium is WAY faster.
Probably a large cache effect.
this
Interesting to compare the performance numbers given for the Itanium
running Glucas v2.8c against my Thunderbird running mprime v21.4 :
- At the smallest FFT length, the Itanium is WAY faster.
this performance difference decreases until
- At FFTs 640K-2048K, the Itanium is a little
At 09:44 AM 10/20/2001 -0500, Mikus Grinbergs wrote:
then the performance difference increases until
- At the largest FFT length, the Itanium is noticeably faster
Is it memory-bandwidth that lets the Itanium pull ahead at the
large FFT lengths ?
Just speculation, it could be the larger
