If this is an upgrade, I'd just go with some more memory to see if that helps. A lot easier to do and you should be a huge improvement if you're going from anything below 1024mb.
If you run out of memory you need more memory regardless of CPU speed.
We arent going to be able to tell you if you will run out of memory (unless you tell us what you are using, how much free memory you have, the operations you will be performing on how many samples loaded into memory and the size of each sample).
You can do that so try it and see if you run out of memory.