Hi, I am doing some performances measurements with Sage/scipy. It's matrix x matrix multiplication (not a very new benchmark....).
It appears that, on the same computer Sage version 8.0 uses Openblas with multithreading, but not Sage version 8.1.beta3: -Example (4 core, broadwell, 3.4ghz. Peak performance 217 Gflops !): size of matrices: 640 -> Sage version 8.0 : Gflops= 138.359946456 Portion peak perf = 0.6358 (top says %cpu=400) -> Sage version 8.1.beta3: Gflops= 48.5945679306 Portion peak perf = 0.2233 (%cpu=100) Both of Sage versions where compiled from source. My questions: Will OpenBlas be fixed to 1 thread in the next versions of sage? t.d. -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
# Broadwell architecture, 4 core, 3.4 Ghz
# Each cpu as 2 vector ports (AVX), each one doing 4 vector operations
# y=a*x + b (that is: 8 flops) by clock cycle.
ncore = 4
freq = 3.4*10^9
vector_ports = 2
perf = 8*vector_ports*ncore*freq
print "Peak perf, Gflops:",perf
for n in [10*2^i for i in [1..10]]:
c= random_matrix(RDF,n)
d= random_matrix(RDF,n)
t= timeit("c*d",seconds=True)
flops= 2*n^3/t
print n,t,"Gflops= ",flops/10^9," Portion peak perf = ",flops/perf
#
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