World Editor Lags like CRAZY! Little help here?

Let's take the map Italy, which I'm currently using to create a mod...

To understand just how bad it is, I usually average around 70fps ingame,
(In this particular play I had 3 cars loaded and was looking at the bay which I understand contains a ton of details)



Now here's what I average whenever I start working with the World Editor:



It kinda bugs me but I can understand the stress when loading details...

But sometimes it just gets so low i can't even understand if my GPU is running properly:





Is this a common problem? Doesn't appear it is to me, since I had to create a whole thread for this

hope someone can tell me what's wrong or if this is normal