choppy editor with inspector visible

I get really strange choppy editor experience when testing the game, and a little bit in general. While I realise that running the game in editor is going to be worse than standalone, my machine isn’t a slouch and it has a definite pattern to it-
If I’m inspecting an item that is actively moving/etc it will be choppy in a weird fashion. It’s like it’s running at ‘60frames in one second, but followed by a quarter second of no frame.’ So it will move smoothly and then stop.

It’s definitely editor+(hardware specific?) related, like if something is being inspected or if items are being created or destroyed (hierarchy).

For what it’s worth my machine is a - Phenom || six core 1100t black edition.
Geforce GT440 1gb factory overclocked.
It is a 64bit version of windows 7 home.
Not going to win any ‘legendary’ awards but definitely not slow. One reason I think the machine IS important is my wife’s rig (which is a mirror) has a similar issue. Any help?

It’s fixed and I have no real idea why. Thanks all that responded.
I have an auto notifier for driver updates from the motherboard, so that’s possibly it.
I also took a look at the app settings in Nvidia’s control panel and changed the multi-display mixed gpu setting for unity. I thought that was it but even when I changed it back it still works fine. Even so maybe it was ‘woke’ somehow that way.

Again, thanks all that responded.