[gmx-users] Single core Quad processor or Dual processor Dual core?

[Lubos Vrbka]

hi,

i tested DPPC on our dual dualcore opteron machine. unfortunately i 
lost the results and cannot do the tests right now. however, i have the 
results for quad dualcore opteron (i.e., speedup up to 8 processors). i 
remember that the scaling was very similar between the two machines... 
in both cases, each processor had 1 gb of RAM (i.e. 4/8 GBs total, 
respectively)

the numbers follow. first row is number of processors, second line the 
speedup.

DPPC	1	2	3	4	5	6	7	8
opteron	1,0	2,5	3,7	4,9	5,8	6,7	7,6	8,8

setup - lam-7.1, intel compiler version 9. on the dual dualcore machine 
it was lam-7.1, pgi 6.1. the bigger machine is not owned by us and there 
is not yet pgi compiler on it, so i couldn't try gromacs with pgi there...

hth,

-- 
Lubos
_ at _"