Hybrid, Discrete, Overclocking?

The MSI Pulse GL66 does not feature a user-adjustable MUX switch. As such, Optimus is enabled at all times, which does do a pretty good job of making sure you have the GPU power you want when you ask for it. You can also overclock the GPU core and memory from within the MSI software, although power limits are in place both when plugged in and unplugged.

The BIOS by default is fairly locked down, so there's no adjusting of clocks of any sort by default, and even with added controls opened up, adjustments are minimal. You can adjust memory voltage and timings along with the CPU multiplier a little bit if you really must, but I did not confirm whether these adjustments actually made any difference.