Which PC performance are necessary for the electromagnetic simulations?

Hello,
if I wanted to do electromagnetic simulations using, for example, the CST, what is the most important parameter of PC that I should take into account? Is it important the processor, the RAM, or the graphics card?

Many thanks in advance.
Regards

Antonio

Processor (and RAM) clock frequency & amount of RAM

Depends on the problem size and complexity but experiences say double Xeon E5 series, and 32GB or more RAM will be ideal for 3D EM simulations.
But small sized problems,( planar structures,patch antennas,MS resonators etc. ) i7+16GB is also good enough.Also some EM simulators such as HFSS eat huge RAM, some of them not.

-graphics card performance(opengl)
-RAM size as much as possible,
-processor with higher cache memory

in the order of preference

there are many layers of ownership for most of the simulation programs. If you are using base versions they use single core so CPU Speed is the most important after that ram speed and capacity is important for mesh intensive structures. For example CST can use hyperthreading and hardware acceleration(Graphics Card) but they need more expensive license to unlock those features.

Multithreading should be standard by now. All the 2.5D and 3D EM solvers I am using have this for many years now.
What solver and version do you refer to that uses only a single core?

When I was using FEKO about 3 years ago it wasn't supporting it or at least disabling multithreading was recommended for increased performance.

Theoretically shouldn't be as important as graphic card performance, processor speed, or the size of the RAM or cash memory, but during years the biggest improvement that I found using EM simulators, was when I switched from a standard HardDisk to SSD drive, even the RAM size was the maximum supported by the PC.
There is always information that is written on the hard-drive during EM simulation, so faster hard-drive will make the difference.