MultiGPU Bug

gistfile1.py

import simtk.openmm
import simtk.unit as unit
import math

state = simtk.openmm.XmlSerializer.deserialize(open('state.xml').read())
system = simtk.openmm.XmlSerializer.deserialize(open('system.xml').read())
for i, force in enumerate(system.getForces()):
    force.setForceGroup(i)
system.getForce(3).setReciprocalSpaceForceGroup(6)

properties = {"OpenCLPlatformIndex": "0", "OpenCLDeviceIndex": "0,1"}

integrator = simtk.openmm.XmlSerializer.deserialize(open('integrator.xml').read())
gpuContext = simtk.openmm.Context(system, integrator, simtk.openmm.Platform.getPlatformByName('OpenCL'), properties)
gpuContext.setState(state)

integrator2 = simtk.openmm.XmlSerializer.deserialize(open('integrator.xml').read())
refContext = simtk.openmm.Context(system, integrator2, simtk.openmm.Platform.getPlatformByName('Reference'))
refContext.setState(state)

group = 3
gpuForces = gpuContext.getState(getForces=True, groups=1<<group).getForces()
refForces = refContext.getState(getForces=True, groups=1<<group).getForces()

mse = 0
for i, (f1, f2) in enumerate(zip(gpuForces, refForces)):
    diff = f1 - f2
    error = (diff[0]*diff[0]+diff[1]*diff[1]+diff[2]*diff[2]).value_in_unit(unit.kilojoules**2/(unit.nanometers**2*unit.moles**2))
    if(error > 2000):
        print(f1, f2)
        print(i, error)
    mse += error
mse = math.sqrt(mse/len(refForces))
print('RMSE: ', error)