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

[Justin Lemkul]

On 3/19/20 1:01 PM, Jochen Hub wrote:
> 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?
>

Sounds to me like an important bug that should be reported on Redmine. 
There was a COM motion bug that was fixed in 2020.1 but perhaps there 
are lingering issues.

-Justin

-- 
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Justin A. Lemkul, Ph.D.
Assistant Professor
Office: 301 Fralin Hall
Lab: 303 Engel Hall

Virginia Tech Department of Biochemistry
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jalemkul at vt.edu | (540) 231-3129
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