Users January 2020

users@lists.einsteintoolkit.org

15 participants
20 discussions

ET on AMD Epyc cores?
by Geraint Pratten 21 Jan '20

21 Jan '20

Hi everyone, Does anyone have any experience running on AMD Epyc cores? It seems that these are becoming quite trendy and I found a pretty decent best practice guide that Prace released http://www.prace-ri.eu/best-practice-guide-amd-epyc However, whenever I've compiled ET recently its typically been on Intel cores + Intel compiler + Intel MKL etc. However, Intel MKL is notorious for being subotpimal on non-Intel cores. Does anyone know of any possible issues that could arise when running ET on AMD Epyc cores? Similarly (and likely optimistically), has anyone had the chance to benchmark the performance of ET on the AMD cores? Thanks! Geraint

2 2

Agenda for Thursday's Meeting
by users＠einsteintoolkit.org 20 Jan '20

20 Jan '20

Please update the Wiki with agenda items for Thursday's meeting. Thanks! https://docs.einsteintoolkit.org/et-docs/meeting_agenda --The Maintainers

1 0

PhD positions at Perimeter Institute and the University of Guelph
by Daniel Siegel 20 Jan '20

20 Jan '20

Hi everyone, I would greatly appreciate your forwarding this advertisement to interested candidates. Thanks! Daniel -- Daniel Siegel Assistant Professor Perimeter Institute for Theoretical Physics Department of Physics, University of Guelph http://www.perimeterinstitute.ca/people/daniel-siegel <http://www.perimeterinstitute.ca/people/daniel-siegel> --- Ph.D. Position in Theoretical Astrophysics at Perimeter Institute Applications are invited for one or more PhD positions in gravitational-wave and multi-messenger astrophysics at Perimeter Institute for Theoretical Physics <https://www.perimeterinstitute.ca/> and the University of Guelph <https://www.physics.uoguelph.ca/>, to start Fall 2020 or earlier. Successful applicants will work with Assistant Professor Daniel Siegel <https://www.perimeterinstitute.ca/people/daniel-siegel> on numerical simulations of compact binary mergers and associated electromagnetic counterparts. One position will be linked to the Canadian Astroparticle Physics Research Institute (Arthur B. McDonald Institute <https://mcdonaldinstitute.ca/>) and explore the interface of neutron star mergers and neutrino physics. Successful applicants will benefit from Perimeter’s thriving international and multi-disciplinary research community with ample opportunity to collaborate within and across fields. They will be embedded in a unique combination of Perimeter’s strong gravity community, the newly established Gravitational Waves Initiative <https://www.perimeterinstitute.ca/research/research-initiatives/gravitation…>, as well as the Astrophysics and Gravitation Group <https://www.physics.uoguelph.ca/astrophysics-and-gravitation> at the University of Guelph. More information on PhD opportunities at Perimeter can be found here <https://www.perimeterinstitute.ca/training>. Evaluation criteria for the positions include academic record, prior research experience relevant to the position as well as commitment to fostering an inclusive research environment. Candidates from underrepresented groups in theoretical astrophysics are strongly encouraged to apply. Successful candidates will receive their degree from the University of Guelph, one of Perimeter’s partnering universities. Interested candidates must typically hold a MSc degree in Physics and need to apply through the Guelph-Waterloo graduate program, the largest physics & astronomy graduate program in Canada: https://www.physics.uoguelph.ca/graduate-studies/prospective-graduate-stude… <https://www.physics.uoguelph.ca/graduate-studies/prospective-graduate-stude…>. In addition, interested candidates should submit a CV and cover letter to dsiegel(a)pitp.ca <mailto:dsiegel@pitp.ca> summarizing the candidate’s motivation for this PhD position as well as prior research experience relating to gravitational-wave and multi-messenger astrophysics. Candidates should also comment on their numerical and computational skills. Deadline for applications is February 1st, 2020. Late submissions may be considered until the positions are filled.

1 0

WENO-Z in GRHydro
by Bruno Giacomazzo 17 Jan '20

17 Jan '20

I just discovered that GRHydro supports also WENO-Z (a different implementation of the WENO 5th order reconstruction scheme). I have a master student currently looking at high order schemes and I admit that I thought that GRHydro had only WENO5 implemented (recon_method="weno") since this is the scheme that was mentioned and tested in the GRHydro paper (which instead does not mention WENO-Z which I assume was probably implemented after the paper). Has the WENO-Z implementation also been tested? Is someone using it? Thanks, Bruno -- Prof. Bruno Giacomazzo Department of Physics University of Milano-Bicocca Piazza della Scienza 3 20126 Milano Italy email: bruno.giacomazzo(a)unimib.it phone: (+39) 02 6448 2321 web: http://www.brunogiacomazzo.org ---------------------------------------------------------------------- There are only 10 types of people in the world: Those who understand binary, and those who don't ----------------------------------------------------------------------

3 4

Meeting Minutes for 2020-01-09
by Gabella, William E 16 Jan '20

16 Jan '20

Present: Liu Haoyang, Zhao Zhi-Chao, Bill Gabella, Zach Etienne, Steve Brandt, Roland Haas Chair: Steve Minutes: Bill * ETK Workshop at LSU in August 2020. o Likely August 3-7, the first week. Let Steve know what you would like to see there. Planning on student tutorial, will have students from LSU. o Some money for travel support---if you have a student you want to send ask Steve. o NRPy tutorial would be nice---Zach agrees. NRPy spreading around China; Zach back from a recent visit there. * Any information about an ETK workshop in Europe? Need to know and coordinate schedules. * Working group update: Performance Optimization AMRex o AMRex work with Erik and Steve. AMRex is a mesh refinement library developed by the DoE specifically by LBNL in California. Built-in support for tiling and multi-threading. Erik, Steve, and Roland, try to use AMRex as an underlying driver for Cactus. Have wave equation working. Roland visited Erik for a week over break, mesh-refinement code in there, and Zach's Baikal BSSN code that can evolve Minkowski ST without failing. And can do Schwarzschild BH with two puncture, until it fails. Likely the boundary conditions are wrong. Using two punctures as initial data. Is a Cactus thorn. Looping over grid points is different, so not backward compatible. Developed as a hydro code. Supports two kinds of variables, cell-centered and vertex-centered, which is not supported in Cactus at all. Metric is vertex-centered. AMRex uses the PreSync infrastructure of the Cactus branch Steve has been working on. Code is public. Repo cactusamrex in Erik's account (see below). Is the docker file Erik uses for testing. Need latest version of cmake. Erik is working on BCs other than periodic, Dirichlet and Reflection. Is a work in progress, but at a point where we can take Minkowski or Schwarzschild ST and run on a cluster and see how the framework scales---effects on run speed, etc. All refinements are on the same time step. o For Minkowski ST when evolve quantities 0 or 1 at least it does not die, but not sure if it is still 0 or 1, responding to Steve's question. o Took Zach's notebook and re-wrote the glue for it to work. Kept the physics the same. o Links: https://bitbucket.org/eschnett/cactusamrex/src/master/ https://amrex-codes.github.io/<https://amrex-codes.github.io/> o Zach suggested a trumpet BH solution with corresponding gauge conditions, guaranteed to be static ST, and is a good test. Also numerically stable; shows up in the original NRPy paper. * Steve wants to get rid of cactuscode.org and make it a web page on ETK website. Should have an example web page for next week. * Next release, 6 months from late October, so maybe April. o Volunteer for heading the release needs to be determined. * Roland has some bug fixes to back port to the release. o System topology thorn will fail if using new (2.X) of hwloc library. Small change to the search. o In the ticketing system with "backports" in the subject. He would like to do this. Steve will look at the tickets and commits. https://bitbucket.org/einsteintoolkit/tickets/issues/2314/ o Maybe some updates for simfactory machines, but those get updated all the time. [edited for readability-my paragraph (non)wrapping looked like hell on lists.einsteintoolkit.org, finally put in hard breaks with shift-return in Thunderbird, bill]

4 4

Einstein Toolkit Meeting Reminder
by users＠einsteintoolkit.org 15 Jan '20

15 Jan '20

Hello, Please consider joining the weekly Einstein Toolkit phone call at 9:00 am US central time on Thursdays. For details on how to connect and what agenda items are to be discussed, use the link below. https://docs.einsteintoolkit.org/et-docs/Main_Page#Weekly_Users_Call --The Maintainers

1 0

Agenda for Thursday's Meeting
by users＠einsteintoolkit.org 13 Jan '20

13 Jan '20

Please update the Wiki with agenda items for Thursday's meeting. Thanks! https://docs.einsteintoolkit.org/et-docs/meeting_agenda --The Maintainers

1 0

Meeting Minutes for 2020-01-09
by Gabella, William E 09 Jan '20

09 Jan '20

1 0

Einstein Toolkit Meeting Reminder
by users＠einsteintoolkit.org 08 Jan '20

08 Jan '20

1 0

Agenda for Thursday's Meeting
by users＠einsteintoolkit.org 06 Jan '20

06 Jan '20

Please update the Wiki with agenda items for Thursday's meeting. Thanks! https://docs.einsteintoolkit.org/et-docs/meeting_agenda --The Maintainers

1 0

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

Users January 2020