James
Also, what constraints are calculated by LazEv?
-erik
On Mon, Jul 27, 2015 at 4:56 PM, Erik Schnetter schnetter@cct.lsu.edu wrote:
Jim
Thanks for posting the details.
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?
For the new McLachlan, you would probably use the built-in dissipation instead of thorn Dissipation, which should lead to a small speed-up.
-erik
On Mon, Jul 27, 2015 at 4:43 PM, James Healy jchsma@rit.edu wrote:
Hello,
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.
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.
Below is a summary of the results as reported at iteration 256 from Carpet::physical_time_per_hour:
McLachlan - rewrite branch: 3.0596110 M/hr McLachlan - master branch: 3.8033607 M/hr LazEv - 4.1941544 M/hr
I am using the stampede-impi.cfg configuration file in simfactory. "module list" returns:
- TACC-paths 3) cluster-paths 5) xalt/0.4.6 7) TACC
- Linux 4) intel/13.0.2.146 6) cluster 8) impi/4.1.0.030
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?
ML_BSSN::harmonicN = 1 # 1+log ML_BSSN::harmonicF = 2.0 # 1+log ML_BSSN::ShiftGammaCoeff = 0.75 ML_BSSN::BetaDriver = 1.0 ML_BSSN::LapseAdvectionCoeff = 1.0 ML_BSSN::ShiftAdvectionCoeff = 1.0
ML_BSSN::MinimumLapse = 1.0e-8
ML_BSSN::my_initial_boundary_condition = "extrapolate-gammas" ML_BSSN::my_rhs_boundary_condition = "NewRad" Boundary::radpower = 2
ML_BSSN::ML_log_confac_bound = "none" ML_BSSN::ML_metric_bound = "none" ML_BSSN::ML_Gamma_bound = "none" ML_BSSN::ML_trace_curv_bound = "none" ML_BSSN::ML_curv_bound = "none" ML_BSSN::ML_lapse_bound = "none" ML_BSSN::ML_dtlapse_bound = "none" ML_BSSN::ML_shift_bound = "none" ML_BSSN::ML_dtshift_bound = "none"
ML_BSSN::fdOrder = 8
ActiveThorns = "Dissipation"
Dissipation::order = 5 Dissipation::vars = " ML_BSSN::ML_metric ML_BSSN::ML_trace_curv ML_BSSN::ML_curv ML_BSSN::ML_Gamma ML_BSSN::ML_lapse ML_BSSN::ML_shift ML_BSSN::ML_dtlapse ML_BSSN::ML_dtshift "
ActiveThorns = "ML_ADMConstraints"
Thanks, Jim Healy
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-- Erik Schnetter schnetter@cct.lsu.edu http://www.perimeterinstitute.ca/personal/eschnetter/