To put it another way, with regular simple office usage, in terms of power utilization it will behave like a CPU with integrated graphics for an ultra low power ultraportable. However for heavy workloads, it will behave like a high end workstation with high end desktop CPU and high end mobile GPU, but only drawing mid-tier power levels.
With low to moderate usage, this will be silent. With very heavy usage, fan noise will be audible, but it will be nowhere near as bad as the Intel & AMD laptops with discrete graphics.