[pmax]

A couple thoughts come to mind:
- Try suppressing _all_ constraints (easy to do if you change to Model view at the top of the browser), to see if indeed conflicting constraints are the culprit. If you already have a mix of suppressed constraints and do not want that lost, then either close and do not save once you have investigated, or Undo.

- LODs should help, but if you are seeing such dramatic performance issues, I do not suspect the memory is a problem.

Also, LODs are designed to respect constraints, even if the component is suppressed, so if the issue is indeed constraints, the LODs will not help.

- Assembly Features can cause performance issues if used too liberally. Generally I recommend keeping them in subassemblies as best possible, instead of high up in top assemblies.

- Are you using a Space Mouse? We have seen driver issues in the past, causing just this kind of multi-minute delays.

Regards,
Pete
Autodesk