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

[Jochen Hub]

Hi Magnus and Justin,

Am 23.03.20 um 13:52 schrieb Magnus Lundborg:
 > Hi Jochen,
 >
 > Have you tested if this happens with -update cpu? Perhaps it's the 
bonded on GPU that's the problem, unrelated to updating.

The problem only appears with -update gpu, not with -update cpu.

  I didn't see a
 > Redmine issue yet. Could you make one?

I tried, but I seem to lack permissions: On

https://redmine.gromacs.org/projects/gromacs/issues/new

I get "You are not authorized to access this page." Did I miss something 
here?

Thanks,
Jochen


Am 23.03.20 um 13:52 schrieb Magnus Lundborg:
> Hi Jochen,
> 
> Have you tested if this happens with -update cpu? Perhaps it's the 
> bonded on GPU that's the problem, unrelated to updating. I didn't see a 
> Redmine issue yet. Could you make one?
> 
> Cheers,
> Magnus
> 
> On 2020-03-19 18:01, 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?
>>
>> Cheers,
>> Jochen
>>
> 

-- 
---------------------------------------------------
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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