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<div class="moz-cite-prefix">Hi Erik,<br>
<br>
We evolve alpha and beta for the gauge variables as given in
equations 7a and 7b of <a class="moz-txt-link-freetext" href="http://arxiv.org/pdf/1506.06153.pdf">http://arxiv.org/pdf/1506.06153.pdf</a>. The
number I reported for LazEv was using 5th order dissipation
applied to all 21 evolved variables (alp, beta^i, At_{ij},
gt_{ij}, Gammat^{i}, trK, and xi). <br>
<br>
LazEv is calculating the Hamiltonian and Momentum constraints as
well as the constraints on Gammat^i using 4th order stencils. <br>
<br>
I also forgot to mention that I did these tests on 16 nodes, and
the memory usage was relatively low ( ~2 GB/MPI process ).<br>
<br>
I will give the internal dissipation for McLachlan a try.<br>
<br>
Thanks,<br>
Jim<br>
<br>
On 07/27/2015 05:56 PM, Erik Schnetter wrote:<br>
</div>
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cite="mid:CADKQjjcf4wV3yYBPoLHBFYFzSYMf8gZpCDVMm6aimWzidPSKuw@mail.gmail.com"
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<div dir="ltr">Jim
<div><br>
</div>
<div>Thanks for posting the details.</div>
<div><br>
</div>
<div>Can you give us more details about the LazEv scheme? In
particular there may be differences in the gauge. What (gauge)
variables do you evolve? What gauge conditions do you use? And
what kind of dissipation do you apply? Can you point us to the
source code?</div>
<div><br>
</div>
<div>For the new McLachlan, you would probably use the built-in
dissipation instead of thorn Dissipation, which should lead to
a small speed-up.</div>
<div><br>
</div>
<div>-erik</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Mon, Jul 27, 2015 at 4:43 PM, James
Healy <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:jchsma@rit.edu" target="_blank">jchsma@rit.edu</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">Hello,<br>
<br>
I have been running some tests on Stampede comparing the run
speed of McLachlan to RIT's evolution thorn LazEv. I
started with the qc0-mclachlan.par parameter file included
with the Einstein Toolkit, added a few refinement levels,
increased the resolution and changed McLachlan to be 8th
order (and increased the number of ghost zones to 5). I
also increased the initial separation so the finest grids
aren't already overlapping. To compare with LazEv, I
removed the McLachlan and Dissipation thorns and replaced
them with LazEv. Everything else in the parameter file is
exactly the same. I tried using both the McLachlan master
and rewrite branches.<br>
<br>
The grid setup is 10 levels of refinement, dx=4M on the
coarsest with outer boundary at 400M, M/128 on the finest
with r=0.6M, CFL is 0.25. Both use 8th order spatial
differencing with ghost_size=5 and 5th order dissipation.<br>
<br>
Below is a summary of the results as reported at iteration
256 from Carpet::physical_time_per_hour:<br>
<br>
McLachlan - rewrite branch: 3.0596110 M/hr<br>
McLachlan - master branch: 3.8033607 M/hr<br>
LazEv - 4.1941544 M/hr<br>
<br>
I am using the stampede-impi.cfg configuration file in
simfactory. "module list" returns:<br>
<br>
1) TACC-paths 3) cluster-paths 5) xalt/0.4.6 7)
TACC<br>
2) Linux 4) intel/<a moz-do-not-send="true"
href="http://13.0.2.146" rel="noreferrer" target="_blank">13.0.2.146</a>
6) cluster 8) impi/<a moz-do-not-send="true"
href="http://4.1.0.030" rel="noreferrer" target="_blank">4.1.0.030</a><br>
<br>
Attached is my parameter file. I pasted the McLachlan
parameters below. Are there any optimizations that I can
use for McLachlan? Are the parameters I am using for it what
would be used for production runs?<br>
<br>
ML_BSSN::harmonicN = 1 # 1+log<br>
ML_BSSN::harmonicF = 2.0 # 1+log<br>
ML_BSSN::ShiftGammaCoeff = 0.75<br>
ML_BSSN::BetaDriver = 1.0<br>
ML_BSSN::LapseAdvectionCoeff = 1.0<br>
ML_BSSN::ShiftAdvectionCoeff = 1.0<br>
<br>
ML_BSSN::MinimumLapse = 1.0e-8<br>
<br>
ML_BSSN::my_initial_boundary_condition =
"extrapolate-gammas"<br>
ML_BSSN::my_rhs_boundary_condition = "NewRad"<br>
Boundary::radpower = 2<br>
<br>
ML_BSSN::ML_log_confac_bound = "none"<br>
ML_BSSN::ML_metric_bound = "none"<br>
ML_BSSN::ML_Gamma_bound = "none"<br>
ML_BSSN::ML_trace_curv_bound = "none"<br>
ML_BSSN::ML_curv_bound = "none"<br>
ML_BSSN::ML_lapse_bound = "none"<br>
ML_BSSN::ML_dtlapse_bound = "none"<br>
ML_BSSN::ML_shift_bound = "none"<br>
ML_BSSN::ML_dtshift_bound = "none"<br>
<br>
ML_BSSN::fdOrder = 8<br>
<br>
ActiveThorns = "Dissipation"<br>
<br>
Dissipation::order = 5<br>
Dissipation::vars = "<br>
ML_BSSN::ML_metric<br>
ML_BSSN::ML_trace_curv<br>
ML_BSSN::ML_curv<br>
ML_BSSN::ML_Gamma<br>
ML_BSSN::ML_lapse<br>
ML_BSSN::ML_shift<br>
ML_BSSN::ML_dtlapse<br>
ML_BSSN::ML_dtshift<br>
"<br>
<br>
ActiveThorns = "ML_ADMConstraints"<br>
<br>
<br>
Thanks,<br>
Jim Healy<br>
<br>
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<br>
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</div>
<br>
<br clear="all">
<div><br>
</div>
-- <br>
<div class="gmail_signature">Erik Schnetter <<a
moz-do-not-send="true" href="mailto:schnetter@cct.lsu.edu"
target="_blank">schnetter@cct.lsu.edu</a>><br>
<a moz-do-not-send="true"
href="http://www.perimeterinstitute.ca/personal/eschnetter/"
target="_blank">http://www.perimeterinstitute.ca/personal/eschnetter/</a></div>
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