System Spec Questions

[Nicias]

Hi,

I recently got into KSP, and I'm playing it on my old iMac. It works, but just barely.

The only mod I have installed is MechJeb. Launching a Kerbal X, doesn't even run full speed. The clock turns yellow and orange. Once I get into space, things are fine. This is with all of the graphics options turned all the way down. 

I plan on getting a new computer, a Dell XPS 13 laptop, and wondered if I could expect better performance. Here are the relevant specs:

 iMac: Core 2 Duo (3 GHz), 4GB RAM, NVIDIA GeForce 9400 w/ 256MB 

Laptop:  i5-6200U up to 2.80 GHz,  8GB RAM, Intel HD Graphics 520 (integrated)

I might also wait and get the Kaby Lake version when it comes out.

Should I expect significant improvement on this new machine?

Thanks!