long time while simulate conductor

i only have a cylindrical conductor (copper) with 2 wave port on top and bottom faces
simulate from 0-10 ghz it takes a very long time and give warning" large mesh"any one know to to suppress this warning and decrease the simlation time?
numerical values will be better

Wha software do you use? What is conductor length, what is diameter? What are you looking for - field radiation or?

hfss
D=50 um
L=100 um
i search for getting the equivalent spice circuit