Running CAD and the solver in parllel


In Device latest version (6.0.1044) the solver and the CAD are linked as follows:

  1. It is impossible to send the Charge based calculation to the queue if the CAD is open. This is true even when the Charge is set to ‘false’ in the Resource tab.

  2. While the solver (Charge) is running in the queue, it is impossible to view simulation results in the already completed simulation files. In addition, although the basic editing of the structures is possible adding new implants is not allowed.

This linkage between the CAD and simulation engine does not exist in the FDTD and is inconvenient for Device. Ideally, viewing simulation results and editing simulation files shall not be impacted by the engine run.

Note, it is possible that the same behavior existed in previous versions as well.


Hi @ibayn,

You are right. The behavior of DEVICE and FDTD is quite different in this matter that you have mentioned. The DEVICE simulations used to behave similar to FDTD ones in its older versions (v.4 and older). However this changed when the HEAT solver was introduced to the DEVICE design environment. In order to accommodate two different solvers that can be licensed separately the behavior of DEVICE had to be changed. Thus from version 5 and onward, you need an available engine license (on top of the CAD license) to open up the DEVICE CAD. Please note that this issue will not occur if you are running the job queue and opening up the CAD in the same computer because DEVICE allows users to open up as many instances as needed (and run as many parallel simulations as possible) on the same computer with just one pair of CAD and engine license. However, since you are running the queue in a separate machine (it seems), the remote machine is checking out an engine license to run the simulations and therefore you no longer have an engine license available to open up the CAD in your machine.

A workaround would be possible if you had a HEAT license as well (or of course if you had an extra CHARGE license!). In that case the remote machine would check out the CHARGE engine license but you could still open up the CAD in your machine using the HEAT engine license. However please note that in that case you would be able to see the results but not modify any of the parameters of the CHARGE solver or its children.