The hardware requirements for MIKE SHE depend on the model that you are trying to simulate. As a rule of thumb, any good quality, new computer should be sufficient for an average MIKE SHE model. Thus, a typical machine for an average MIKE SHE model will have at least a 2GHz CPU, 8-16GB of RAM, and 100-500 GB of free disk space.
However, these are minimum requirements. In particular, data storage is often a problem. A large model with a long simulation period and a short saved time step interval can easily generate very large output data sets. If you save multiple simulations (e.g. calibration runs or scenarios), then you can quickly have hundreds of Gigabytes of output data.
Note: MIKE SHE must run in a Windows environment and will not run on Linux workstations.
All of the DHI numerical engines are only compiled for a 64-bit processor, including MIKE SHE.
Multi-core/processor computers
The numerically intensive operations in the MIKE SHE engine have been optimized for multi-core computers. However, not all of the hydrologic processes scale equally well. Thus, the simulation speed improvements on multi-core computers depends on the model.
MIKE SHE always runs with the maximum allowed number of threads, which will not be slower, but may be less efficient if you are running multiple simulations at the same time. There is an extra parameter option ("max number of threads") that you can use to control the parallelization of each simulation. Also, hyper threading is less efficient than physical cores. So, there might also be some benefit to turning off hyper threading for some simulations (This is a BIOS setting).
The AUTOCAL program for parameter optimization and sensitivity analysis has been updated to automatically spread out the simulation load to the available cores.
The standard MIKE Zero license is supports up to eight cores/processors. If you want to take advantage of more than eight cores, then you will need to contact your local DHI sales office to obtain additional run-time licenses.
However, the 2017 Release allows you to use all the cores available. There is no longer any restrictions on the number of cores - as long as you have a Corporate License and valid SMA).
MIKE SHE does not dynamically allocate RAM. That is, the amount of RAM required by the model is allocated at the beginning of the simulation based on the specified number of nodes. If you don’t have enough RAM, then MIKE SHE will swap to the hard disk, which can drastically slow down your simulation.
The amount of RAM may also be important when running multiple simulations at the same time, since each simulation will require a full memory space.
In general, the higher the CPU clock speed, the faster the calculations. However, simulation speed also depends on the chip design, which depends on the manufacturer (e.g. Intel vs AMD), the platform (e.g. laptop vs. desktop), etc. Given the huge range of chip designs and the rapid pace of development, it is difficult to give specific guidance on choice of CPU - other than “faster is usually better, all other things being equal”.
