06-07-2012 08:05 AM
We bought a new HP-UX RX2800 server with Itanium 9320 with hope to increase our application performance and move from RHEL.
But simple OpenMP test shows downgrade of performance. Even with bigger number of threads. Simple parallel loop is very slow on HP-UX. Time = 6 secs. On RHEL this test takes about 1 sec.
As I understand the HP-UX should be faster using more cores.....but no :(
All optimization for HP-UX aCC compiler is on.
for(size_t j = 0; j < N; ++j)
#pragma omp parallel for default(shared) private(i) schedule(static,chunk) reduction(+:result)
for (ssize_t i = 0; i < N; ++i)
result = result + (a[i] * b[i]);
Compiller string: aCC -AA -mt +Ofaster -ipo +Ofltacc=relaxed +Onosize +Oinline +DO11.31 +DSnative +DD64 +Oopenmp
Is anyone know the problems with this? Any suggestions?
Thanks for help.
06-07-2012 09:01 AM