So I just bought a new notebook and I'm wondering why Photoshop runs so slow on it. On easy, small files it's fast but on layouts that have a lot of layers & all that it's incredibly slow. The laptop has an i7-3632QM with 8 logical cores, 8GB's of RAM at 1600 MHz and an 8750M GPU and a 750GB WD 5400RPM HDD. Do I need more RAM, should I buy an SSD ?

P.S. I'm using Photoshop CC.