It’s not at least depending on, what you do with the editor.
Editing big maps, aside fps template could be painful.
I updated from a 570ti to 960 and that made not really a big difference for my small project.
But Ram upgrade from 8-16GB did the trick for me.
With 8GB i had always https://.google.de/?gws_rd=ssl#q=ram+rush running visible in my taskbar, to prevent Ram filling up and swapping to HD starts.
Other tasks like skype, i had to disable and browsing also.
For 2D it could be fine enough.