I've used Simulation on very small (<20 parts) assemblies in the past, and I don't remember this happening. I'm working on a 250 part assembly now, and every time I surface mesh, it locks up for 15-30 minutes after I click the "Done" button. During this time AlgFrame doesn't turn red in the task manager/resource monitor, so its not completely locked up, and I see about 20 instances of Alg_Elem.exe writing to the disk in the resource monitor. This gets extremely frustrating when parts fail to mesh, and it takes 30 minutes just to adjust it and try again. The solid meshing process doesn't seem to have this problem, and the actual anaysis only takes about 10 minutes. Seems odd that the surface meshing takes 4x as long as the actual solution.
Well then it is an extremely annoying part of Simulation. It doesn't even use anywhere near the full bandwidth of my SSD when its writing things to disk after surface mesh. Post surface mesh data speeds max out at maybe ~5MBps. Post solid mesh write speeds top out at ~250MBps.