My previous computer was i7 4-core 3.7ghz with 16GB of ram and an entry level GeForce card and my models were opening up pretty quick with no lag and performance was overall quite good. 

I recently switched to Dell Precision T5820 Workstation 3.70GHz 8C W-2145, with 32GB of ram and Qudro P4000 card. It feels like every model is slow. Solidworks takes twice as long to load. Assembly rotation / zoom once