| Re: [eigen] Slow matrix-matrix multiply |
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- To: eigen <eigen@xxxxxxxxxxxxxxxxxxx>
- Subject: Re: [eigen] Slow matrix-matrix multiply
- From: Gael Guennebaud <gael.guennebaud@xxxxxxxxx>
- Date: Tue, 2 Apr 2013 13:00:34 +0200
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On Tue, Apr 2, 2013 at 11:26 AM, Gael Guennebaud
<gael.guennebaud@xxxxxxxxx> wrote:
> I can also reproduce the performance drop with linux/gcc-4.7. However,
> the generated assembly in both cases are extremely similar (see the
> attached files), with even an advantage to Eigen with only 18
> additions compared to 27 for custom_gemm. Frankly, I cannot explain
> the perf difference.
oops, actually my system was a bit too loaded and the results too
random. Stable results with gcc4.7 on an Intel(R) Xeon(R) CPU X5570 @
2.93GHz:
-- Eigen --
Time (in seconds):
Preprocessor 0.050
Residual Evaluations 0.077
Jacobian Evaluations 0.695
Linear Solver 0.945
Minimizer 1.839
Postprocessor 0.001
Total 1.907
-- Custom GEMM --
Time (in seconds):
Preprocessor 0.067
Residual Evaluations 0.085
Jacobian Evaluations 0.712
Linear Solver 0.952
Minimizer 1.901
Postprocessor 0.001
Total 1.990
gael