SolidWorks Performance
Performance almost cut load time in half by selecting load component lightweight (2:55 to 1:34) on our test machine for assembly 02-545410 (other assemblies were cut by half or more)
Per the article from GoEngineer you can do basically everything with light weight assemblies, and if you need a part to not be light weight, you can right click on the part and select Set to Resolved, you can also choose on open an assembly and set components resolved.
Load SOLIDWORKS Assemblies/Components as Lightweight | GoEngineer
If your load time is not close to 1:34 after making the change, you may have another issue with your computer causing it to be slow and request that you submit a Helpdesk ticket.