Assuming the configuration indicated in this Knowledge Base Article. However, when you add memory and such it goes up. Most Mac Pros have a power supply capable of about 900 watts. Generally it is recommended to get a 1500 VA or bigger UPS for the Mac Pro.
On my Mac Pro 2,1 with 16 GB of memory, 4 hard drives, 2 optical drives, an ATI HD 4870 video card, a Black Magic Intensity Pro PCI card, a Highpoint RocketRaid 2314 and two monitors (20 inch and 30 inch Cinema Dispplays) I typically draw 300 watts when idle and screens are asleep to 650 watts when all CPUs are processing video and screens are on.
Most homes can't use a UPS larger than 1500VA nor do you want or need to.
Amazon Cyberpower 1500VA $199 or you could go down to even 1000VA.
you can look up PSU and sizing charts and you want a UPS that can handle 865W (size of your PSU) and also UPS like PSU last longer if you don't try to overload.
So 1000VA minimum depending on quality of it, and your wirng and circuit (should not be sharing other equipment other than say TV, lights).
425W for just MacPro2,1 sounds a bit high unless doing a lot of cpu processing.
Each FBDIMM is 'good for' 10-15W which is a lot.
then PCIe cards and graphics.
Wake from sleep etc though can have higher than standard draw.
Starting back with G5 2003, 1000-1500VA has become standard - and necessary - with tower Macs.
I currently use an APC brand Smart UPS 1300 which gives me about 20 minutes of uptime in the event of a power outage (that is including powering both monitors, external hard drives and any vampire loads from other devices plugged into it). However, I am also running a newer 3,1 (Early 2008) Mac Pro which doesn't seem to use quite as much power as yours reads. (Did you take your reading while doing video editing or something? That seems quite high considering.)
Regardless, I'm happy with the capacity of my UPS considering it gives me enough time to shut down in the event of a lengthy power outage, and the computer should sleep right through it if I'm not around to shut down.
I wrote this thread from work with my wattage from memory. Here's the breakdown now that I'm home:
Mac Pro - average 250W
HP 30" monitor - 75W
Apple Cinema 22": 57W
Since my problem is in this new (pre war NY) apartment, all the outlets are on the same circuit breaker, blowing it is easy if I turn on both ACs while running the computer. Never had this problem in a more modern home with newer wiring. Hence never had a UPS, even though a good idea. I was gambling. Those days are over.
I bought the APC 1500 which turns out to be over kill (almost 900 watts), but more importantly found that the surge outlets always pass through power, so I can't use the APC to cut all power to all my devices when I shut it off during the day while at work. The CyberPower does. Off is off to all outlets. I'm returning the APC because it's more than I need and I want off to be off.
I was going to get the CyberPower 1000 with 600 watts, but while my current needs might not be more than 600W or need sine wave technology, I will someday get a new computer that may possibly need it, so I decided to get their sine wave which was cheap at Amazon and went for their 1350 with 810 watts which is double my needs now, but only about $40 more than the 1000 so you get a lot more wattage for your dollar which I may need in the future. Plus I'll have more run time, if needed.
It took awhile to get to this decision, but I'm happy with it and look forward to it's arrival. Thanks everyone for your input!
I would match the PSU to the UPS, and aim for using 60% load.
Some types of equipment like an a/c or fridge should never be on the same circuit.
A good ZeroSurge line conditioner plus 1300VA
And don't go by what KillAWatt or UPS LCD shows.
Also, any half decent graphic card like ATI 5770 75W PCIe rail + 50-100W from the 6-pin aux connector.
Unfortunately this is an old pre war apartment building and wiring is so old that the protective sheating crumbles in your hand if you touch it like if replacing an outlet or light switch. I'm surprised these buildings, of which there are many here in NYC, don't all go up in flames!
So.. what's on the circuit and what "should" be (your point very well taken) are not in my control. It's a really mess, wire and ciruit wise. Hence me getting the battery backup.
I probably should have had one in LA due to outages, lightening and such but got by without for decades. Lucked out of course. It was risky and I should have always had a battery backup. No lecture needed. I was wrong.
But I have one now. And how!
Thanks everyone for your words of wisdom.
the protective sheating crumbles in your hand if you touch it like if replacing an outlet or light switch.
There are specialty electrical products on the market to deal with exactly that problem.
3M makes a special rubber tape for electrical use (this is NOT ordinary electrical tape) that is not very sticky on the roll, but adheres to itself when stretched. I have used it with great success on the old wiring in my home. It meets the code for 600-Volt rating for insulation. I saw a clever electrician use it and he gave me a partial roll. I recently found it for sale at Home Depot or Lowes.
I have best luck splitting the 1/2 inch roll into 1/4 inch strips to wrap individual wires in a box. A 6 to 8 inch strip can be manipulted and stretched easily and provide coverage for an average wire in an electrical box. Then trim the excess to have the conductor poke out the end the required amount.
If you are working with armor-flex cabling, be sure to also install cheap plastic inserts called "BX anti-shorts" into the end of the armor to prevent chafing and having the conductors short out onto the (grounded) armor.
Yup. Have it. Great stuff. I was more mentioning it to let you all know how antiquated the circuitry here is. The tape will help, but this is at the end of the line of wire at the junction box. I still have the issue of too many outlets being on the same circuit breaker causing the breaker to click off and stop power.