1. First go to your starbound storage folder (example: Steam\SteamApps\common\Starbound\storage).
2. Then open starbound config with notepad.
3. After find vsync and change it to false.
4. Save.
5. Run starbound.

This method helped me now i got 40 fps ingame istead of 10-12

btw last days i spend for performace search and thats what i found: theres an aplication which is turn off 1 cpu function which is pump up fps it called - Cpu unpark. Try it! somehow it helped me 2.
Also theres some function in BIOS which is called Enhanced Half State (or C1E).This should help ppl with weak cpu. Turning off this one is also pump up fps in most of the games.

P.S. ow and the last one thing... Use ingame resolution same as resolution on desktop!

this r mine configs:
vsync - false
zoom lvl - 2
fullscreen - true
fullscreen Resolution - 1280, 1024
and also better run 32 bit version (it works slightly better)
My system:
core 2 duo 1.8, RAM 4gb, video nvidia gforce gtx 645.
About 40-50 fps in outpost.
i hope it will help some1....

oh btw there's 1 known issue:
sometimes fps will drop again...
if it happens just turn fullscreen off, then turn it on again. it will help a bit.
Just trust me.