UPS power supply for HPZ640 with 925 Watt PSU

[markvandam]

I've been reading the various discussions on this website with interest regarding the purchasing of a UPS for a computer and whether the wattage of the UPS has to match and/or exceed the wattage rating of the computer's PSU. The consensus seems to be that it doesn't, but that it has to match and provide a little extra for the actual draw of the machine in use. That said, I recently spoke to a tech support person at cyberpower and they asked me for my computer model, HPZ640, so they could look up the power supply wattage, which is 925 watts. Their recommendation was to get something with a greater wattage rating than the computer's PSU, therefore, the Cyberpower PFC Sine Wave OR1500PFCLCD mini-tower 1500VA 1050W. This is an expensive unit and doesn't even have an ethernet jack. Thoughts? Are the discussions on here all wrong, or was this tech support person offering up some wrong advice.

 

[popatim]

Tech support was 'doing his best' with the little information he had. Its not bad advice but without knowing your current power consumption you can't accurately guess as that HP is highly configurable. Ie - we have no idea what it has in it or what power it actually uses. You can measure your current power with a device like a Kill-a-watt meter or you can get a rough estimate adding up the power used by the various components.

The power rating of the UPS only needs to exceed the power used by the pc when running at max load. For example I have a 300w psu on my server which has a 450w power supply in it. The server actually uses 115w at max load so the UPS is can easily handle the load. The battery in the UPS merely determines how long it can run the server once power is removed. See the runtime chart for the UPS once you determine your load.