General Hardware Recommendations
For systems based on Intel chips, good performance can be achieved by fully loading each node on your cluster. There is little performance to be gained by leaving some cores idle.
For systems based on AMD chips, extensive testing with Forte has not been performed but generally it is better to leave up to half of the cores idle on each node to get the best performance.
For System Coupling runs where Forte is a participant, leaving at least 2 cores free per node is recommended to allow resources for communication between Forte and the other participants. Details on how to do that are given in in the System Coupling documentation using the PartitionParticipants command: Using Parallel Processing Capabilities in the System Coupling User's Guide.
A parallel disk is recommended to get the best performance when Forte is writing spatially resolved solution files.
Guidance on Memory Usage
When running a Forte CFD simulation, the guideline is that the memory (or RAM) usage should not exceed the hardware limit.
Memory usage in a CFD simulation would depend on the cell count, the number of chemical species, and the number of reactions if there is combustion. It is difficult to estimate how much memory it would consume before running the simulation. However, memory_diagnostics.csv is a useful output file from a Forte simulation. It reports the total RAM usage and the RAM usage of each core (process) during the simulation. If running the Forte simulation on a shared-memory Personal Computer, pay attention to the total RAM usage and make sure it does not exceed the system's limit. If running on a Linux cluster where each node has its own RAM, pay attention to the RAM usage of each rank (process) of the Forte simulation and make sure that they do not exceed the RAM limit of each node.
Since the cell count is an important parameter in memory usage, for a large test case with a large number of cells, make sure to use a proper number of cores to compute in parallel. This allows the computational load and memory usage to be split among the cores. General Core Count Recommendations outlines general recommendations on how many cores should be used for each node in such calculations.
Further reading related to the memory issues are given in Memory Related Errors and Memory Error Fixed by Simulation Restart.
Ansys Forte's user interfaces have their own memory requirement to run. Specify
approximately 10 GB of memory for Forte Simulate (if generating preview meshes). To
do so, use the Edit Launcher Preferences 
button in the Forte Launcher. Refer to Java Memory Settings in the Ansys Forte User's Guide for details.