I just connected my 12-Core Mac Pro with w5700x to the new APC BR1500MS a couple days ago. My 3 displays are connected to another APC UPS. The only other things I have connected to the new UPS besides the Mac Pro is a small USB G-Drive and a CalDigit.Okay so I whipped out my Belkin Wemo Insight plug which reads the Wattage and reports via an app. For my setup as you can see in my signature below with two monitors and a 16-core with a Vega II as well as a couple of equipment connected to the same outlet - studio monitors, Thunderbolt 3 dock, and a multi-function laser printer:
- On standby it dips below 300W
- Editing in Premiere Pro application it was hovering below 500W and sometimes peaking above
- There was one spike of 723W. I don't know when it spikes to that level and why
In any case, it's safe to assume with your configuration, 865W should not be a problem.
According to the readout on the new UPS at sleep it is pulling 185 watts, at idle 200 watts, an with light use so far has not gone over 223 watts (from what I have noticed).