Hi, I am running molecular dynamics code on Intel Xeon CPU W3680 @ 3.33GHz, which has 6 cores.
When a single calculation runs, it is done 82seconds but if I run multiple runs like 2 or three simultaneously,
it shows up to 150 seconds, which is almost twice slow. Each run consumes 1-2% of memory (6Gig) and I don't
think it is memory shortage or swapping. I tried "-heap-arrays" or "uliimit -s unlimited" to change stack or heap memory
for dyn. memory but either is not working. Still multiple runs show very bad performance.
Is there any way to get better performance on mutiple runs? Any comment will be very appreciated.
cpu: Xeon CPU W3680 @ 3.33GHz, which has 6 cores. Same resuls with or without Hyperthread.
os: ubuntu 10.4, 64bit
compiling option: ifort -xHost -O3 -ipo -no-prec-div