Greetings!

So, I just placed an order for a new server. The company recommended that I get a 3000W UPS. (!) As best as I could I calculated the following wattage consumption based on benchmarked data or datasheets provided by the manufacturers of each component:

              number        watts     **total watts**

MoBo 1 240 240 CPUs (E5540) 2 80 160 RAID cards (3ware) 2 18 36 RAM (6x4GB) 6 3 18 DVD drive 1 7 7 floppy 1 2 2 RE4 drives 8 7 56 WD20 drives 8 6 48 Intel X25 SSD 2 0.15 0.3 total = 567

So that is for the PSU requirements only. The PSUs in the machine are a 720W for the master node and 800W each for two subsystems. That's a total of 2320W that can be delivered by these PSUs. But that is 4X the amount being consumed, at most, by the components. I didn't count case fans or the eSATA card (3W maybe?) or what the PSUs themselves require but assuming I double or triple my calculations I'm not even remotely close to the 3000W UPS I was suggested to get. They run at least $1100. I could get a 2000W for about $750 or a 1500W for $450 and still be well over my estimated power need. I don't think I need a whole lot of run time in the case of a power outage, maybe 20 minutes max, enough time to shutdown if the power doesn't come on within 5-10 minutes.

Any thoughts? Am I off on my calculations? Did I overlook something major? If so what are your suggestions for a UPS? Thanks!