Build for working in InDesign/Illustrator

Hi,

I'm looking for advice on my build - which is used for graphic design work - mostly InDesign and Illustrator. I'm currently having issues with some more complex files in Illustrator, when moving/resizing, or basically doing anything, it takes a lot of time to process. I'm thinking that the GPU might be a bottleneck (I have used an old one, from my old gaming PC), but on the other side - it's mostly 2D, and as far as I remember Adobe's support for GPU acceleration is not so great.

My current build is:

• CPU: i7-4790k
• GPU: GTX660
• RAM: 32GB
• HDD: SSD for the system, HDD for the files

I can upgrade the existing PC, or replace it with a new one, as the old one would still be of use to my employee, so the budget is as follows:

• If upgrading: ~400 USD
• If replacing with a completely new build: ~1500USD