Which has more effect on software launch times: processor, RAM, or Hard Drive?
The hard drive is the only one that noticeably slows down app launching. 

With RAM, there's no noticeable difference unless you already have many programs open and running.

With CPUs you'll only have one core involved in opening an app, so the differences are tiny even if you're making a large improvement.

The payoff with large amounts of RAM and faster CPUs come after the app is open, but mostly that payoff is only seen when you're multitasking or working with large media files.