What do they do to a std ecu to chip it? Just remove boost limit and thats it?

I changed the chip on my Series1 and they were like chalk and cheese in terms of power. My original chip is by Turbosystems which runs at 1 bar and the other unknown chip (hearts hash diamond yes i know its the wrong code) ran 14 psi but felt much quicker, could this be ignition related possibly less retarded when on boost.

Advice greatly appreciated

Cheers PaulT