[petsc-users] Parallelization efficiency diagnose

[Jed Brown]

"Sun, Hui" <hus003 at ucsd.edu> writes:

> Thank you Jed. I don't know how to use "lstopo" from the hwloc, 

A search engine will solve that problem.

> but I looked up the cores and memory from the hardware overview from
> my MAC, it has
>
> Number of Processors:	1
> Total Number of Cores:	2
>
> Besides, as you said, there are 4 logical cores due to hyperthreading. However, I'm still expecting to get speed doubled because I have 2 real cores. So where is the restriction then? 

Memory bandwidth, as stated in my email and the page I linked.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 818 bytes
Desc: not available
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20141204/1889ecee/attachment-0001.pgp>