Does anyone know roughly how many watts of led's would be required to replace one 150w metal halide bulb?

Right now I'm looking into a 10x3w blue and 6x5w white led setup with a driver that will run them at a max current of 50% (rapid led's nano driver with potentiometer) and I'm curious if this will be enough or if I should shell out the extra money to buy drivers capable of taking them up to 100%.