Hi AMBER community,
I'm currently running temperature-based replica exchange on AMBER for a
soluble protein system using an explicit solvent.
In certain instances, after the replica exchange simulation has been
running smoothly for a good number of steps and exchanges, I suddenly hit a
GPU error:
*Error: an illegal memory access was encountered launching kernel
kClearForces*
*cudaFree GpuBuffer::Deallocate failed an illegal memory access was
encountered*
It seems that this error has been observed in the past, but is the
source/cause known?
For your reference, I use the following input parameters for my t-REMD
simulation:
 &cntrl
  imin=0,          ! Molecular dynamics
  ntx=5,           ! Positions and velocities read formatted
  irest=1,         ! Restart calculation
  ntc=2,           ! SHAKE on for bonds with hydrogen
  ntf=2,           ! No force evaluation for bonds with hydrogen
  WATNAM='TIP3',
  OWTNM='OH2',
  tol=0.0000001,   ! SHAKE tolerance
  ntt=3,           ! Langevin dynamics
  gamma_ln=1.0,    ! Collision frequency for Langevin dyn.
  temp0=XXXXX,     ! Simulation temperature (K)
  ntpr=50000,       ! Print to mdout every ntpr steps
  ntwr=50000,     ! Write a restart file every ntwr steps
  ntwx=50000,       ! Write to trajectory file every ntwc steps
  dt=0.004,        ! Timestep (ps)
  ig=-1,           ! Random seed for Langevin dynamics
  cut=9.0,        ! Nonbonded cutoff (Angstroms)
  ioutfm=1,        ! Write binary NetCDF trajectory
  ntxo=2,          ! Write binary restart file
  barostat=2,      ! Use Monte Carlo barostat (Amber 14)
  ntp=0,           ! No pressure coupling, not supported by AMBER REMD
  ntb=1,           ! Constant volume simulation, NVT
  nstlim=5000, ! Number of MD steps between each exchange attempt
  numexchg=1000, ! Number of exchange attempts during simulation
  nmropt=1,       ! Read in chirality restraints
 /
 &wt TYPE='END'
 /
 DISANG=$RESTRAINTS_FILE
Many thanks once again,
Jason
-- 
Jason Wang
Stanford University, Class of 2018
jwang198.stanford.edu
ᐧ
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Received on Thu Apr 05 2018 - 15:00:04 PDT