2 PSU's or 1 ?

[Fritz]

Which is preferred and why? Right now I'm running 1 PSU per server but I know that with 2 the load is shared. But none of them are coming close to the rated capacity of the PSU's so would I gain anything by running 2? Also, does the 2nd PSU add to the total power draw?

TIA

 

[Evan]

Pretty sure it was STH that did an artical on just this question... Yes it increases total power consumption.
If you don't need the redundancy (ie test system at home) then it just adds complexity.

Edit, found it..
Single or Redundant PSUs - Impact on Power Consumption

 

[Fritz]

Thank you sir. much appreciated.

 

[Evan]

I also seem to recall I think Microsoft OCS v2 systems have a single PSU as well, redundancy handled at the application/VM level. I could be very wrong on this as I was looking now and did not find the reference.

 

[Fritz]

I only have one power source going to the rack so redundancy irrelevant. My main concern was stressing the one psu or the pdu. As it is, I have all the spares I'll ever need.

 

[BackupProphet]

I always pull out the second PSU, for me its just a spare.

 

[cheezehead]

At home I only run a single PSU...second PSU is sitting there but unseated. It will consume more power, how much more depends on the Power Supplies and the Power Distribution Unit. I've seen upwards of 30w extra @110v.

At work dual psu's, going to dual PDU's, fed from redundant UPS units, and generator...don't need a PSU failure causing an outage on prod.