airplanerider,
if you are on the CX 777 fleet then you either have a Trent 892 or 884B under the wing (92,000 capable and 84,000 capable), but the GE powered 777ER only has the 115B (115,000lb thrust) fitted, at the moment there are no other 777ER thrust ratings, not sure if there will be any different thrust ratings in the future.
The Trent engines are 'rechipped' to give the required thrust for the airframe type 777-200 or 777-300 via the Data Entry Plug on the EEC, though it's not actually a chip, the avionics team just swap 2 wires around. You can even have 2 different thrust 'capable' engines fitted, but 'chipped' to produce the same thrust. The a/c systems don't know any different.
Brgd's
N1 Vibes - Happy to be a Source of Useful/less Information
PS - A--P Good Luck!