Most users shopping for a single system, may not consider power consumption when making a purchase, but admins looking to acquire many systems will certainly be interested in this data. We placed a power meter at the electrical outlet to catch the Z1’s power consumption at idle and while under a heavy load. To create the load state, we ran Prime 95 and Furmark simultaneously to whack both the CPU and GPU.
The Z1's power supply is rated to handle 400W, and HP assures us that the PSU supports all of the configurations it offers – easily. That seems to be in evidence here, as the system pushed only 213W at peak.
As for noise, the system is whisper quiet under load. When idle and even when doing basic tasks, the system’s sound never rose above our lab’s hushed environmental noise.