Do I need more RAM?

Sometimes when I switch from object mode to edit mode Blender locks up. I figured out this happens when edge length is turned on and everything is selected so I guess Blender is trying to compute and display all of the lengths. Other times in edit mode, with edge length on and everything selected, Blender is sluggish when I orbit a part.
Would more RAM fix this, or is it my processor speed?
Thanks

What is your CPU, GPU and amount of RAM?

Apparently Edge Length calculation is a CPU single thread task. So if your CPU has weak single threaded performance you will notice it suffer there.

I mention RAM because when I open the task manager after Blender locks up, it typically shows memory at 95% with Blender using up most of that.
My processor is an Intel i3-6006U @ 3GHz. 8 GB RAM. Intel HD Graphics 520. The PC is 2 years old.