Elements is lagging, even with my hardware setup

Hi folks,

another, and last question, but I cannot believe, a lot of projects are lagging, disrupted with clicks, and silences, but I have 16GB installed, and a i7 4710HQ chip under WIN 8.1
Unfortunately does not allow to install more than 16GB, but it even hangs with Sonic SE using 16 MIDI channels, and 2 instruments.
Do you have any recommendation to speed up the system?

Start with a decent audio interface