Re: [Pytables-users] Expr performance with Tables on multicore machines

2012-05-14 Thread Francesc Alted
On 5/14/12 3:12 PM, Anthony Scopatz wrote: On Mon, May 14, 2012 at 3:05 PM, Francesc Alted > wrote: [snip] However, do not expect to use all your cores at full speed in this cases, as the reductions in numexpr can only make use of one thread (this is b

Re: [Pytables-users] Expr performance with Tables on multicore machines

2012-05-14 Thread Anthony Scopatz
On Mon, May 14, 2012 at 3:05 PM, Francesc Alted wrote: [snip] However, do not expect to use all your cores at full speed in this cases, > as the reductions in numexpr can only make use of one thread (this is > because this has not been implemented yet, not due to a intrinsic > limitation of nume

Re: [Pytables-users] Expr performance with Tables on multicore machines

2012-05-14 Thread Francesc Alted
On 5/14/12 2:51 PM, Anthony Scopatz wrote: Hi Johann, Thanks for bring this up. I believe that I have determined that this is not a PyTables / pthreads issue. Doing some profiling npoints=100, I found that most of the time (97%) was being spent in the sum() call (see below). This ratio

Re: [Pytables-users] Expr performance with Tables on multicore machines

2012-05-14 Thread Anthony Scopatz
Hi Johann, Thanks for bring this up. I believe that I have determined that this is not a PyTables / pthreads issue. Doing some profiling npoints=100, I found that most of the time (97%) was being spent in the sum() call (see below). This ratio doesn't change much with different values of np