SP works fine with simple built-in materials. However, when I download and use some complex materials from either Substance Share and Substance Source, SP is extremely slow to respond. It takes around 10 seconds or something to update simple changes. Extremely slow! What might be the cause of this?
I am planning to upgrade my PC but not sure where to start (I have an OK PC) and just want to replace some parts to help SP more usable.
Here is my PC spec



