[gmx-users] 2020.1: comm broken with -update gpu -bonded gpu ?

[Jochen Hub]

Hi developers,

I am running a simple DPPC membrane (Berger force field, PME, 1nm 
cutoff, 4fs time step, all standard) with 2020.1 and

comm-mode                = Linear
nstcomm                  = 100
comm-grps                = DPPC water  ; OR System

but the membrane rapidly drifts along the z direction: approx. once 
across the box per 100ps, and accelerating over time.

This happens only with

mdrun -update gpu -bonded gpu

but not with

mdrun -update gpu -bonded cpu   (no spelling mistake)

(with a GTX 1070Ti).

Also no problems with 2018.6 or 2019.6.

Seems like the center of mass motion removal is broken when doing both 
*bonded and updating* on the GPU. Is this issue known?

Cheers,
Jochen

-- 
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Prof. Dr. Jochen Hub
Theoretical Biophysics Group
Department of Physics, Saarland University
Campus E2 6, Zi. 4.11, 66123 Saarbruecken, Germany
Phone: +49 (0)681 302-2740
https://biophys.uni-saarland.de/
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