What UPS do I need for my New Studio XPS 9000 System

Check out APC highly rated.  I use THIS one on my 720 with a 750w supply

Well, I just recently purchased the Cyberpower PP1100.  Seems to be working just great and it's of a good, solid construction.  No reboots like I was experiencing with my APC Back-UPS.  Just be sure you purchase a UPS with true sinewave output instead of simulated.  You'll probably pay a little more but you'll have fewer issues.

I've never had an issue with a PFC power supply (which almost all of them are nowadays) and a "standard" UPS (whatever that means).

I highly doubt that your PC actually consumes 475W of power. You're more likely in the range of 100-200W unless you have an absolutely top-end processor and graphics card. Add another 100W for a large-ish LCD display, and I would suggest that you should probably be looking at a 500VA or greater UPS.

Note that a higher VA rating won't necessarily get you longer battery life.

I own an APC BX1000 and an APC ES 725. These are both "cheap" UPSes and I've never had a problem with either of them. The BX1000 can hold up three PCs. Battery life isn't spectacular, but it's enough that I can shut down cleanly.

Don't go with an APC Back-UPS.  They don't deliver a true sine wave.  They are fine with most PCs, however, you need a true sine wave with the XPS 9000 because of the type of power supply it uses.  Believe me, I found out the hard way.  If you search this board you'll find another thread of XPS 9000 users who had the same experience. Get a true sine wave UPS or you'll be throwing away your money!

Here's the link to the other thread: http://en.community.dell.com/forums/p/19271845/19679765.aspx?PageIndex=1

Disclaimer: Some people may not like what I post here, but it's the truth, so deal with it.

The problem with StudioXPS 9000's and non-pure sine wave UPSs is known and documented.

The two claims associated with the issue is usually this:

1) "Your UPS does not output pure sine wave power and is thus incompatible with PFC/APFC power supplies" OR

2) "Your UPS does not provide sufficient power to maintain system power"

BOTH are FALSE.

The problem is the power supply that Dell has selected for the StudioXPS 9000.

I have tested several well known APFC power supplies, including a Corsair TX650 (which I recommend) and all of the symptoms went away.  The system maintained power when the UPS switched to battery and I could unplug the UPS (forcing it to battery) and power the system completely up with no issues (such as the rapid power cycling)

So you can spend $400-$500 for a UPS "adequate" for the grand StudioXPS 9000 (a notion that is nothing less than pretentious) or you can swap the power-supply for $60.

What Dell should do is replace the power supplies.  There is nothing special about the components of the StudioXPS 9000 that require the AC source to be pure sine wave. 

Please note, personally, and professional I use Dell systems for the majority of deployments (Optiplex/Latitude), so I'm not hating on Dell.

I hope this helps.

Dell has apparently corrected this power supply problem in the new Studio XPS 9100.  My 9100 works just fine on my old APC BackUps Pro 650.  I can cut the power to the UPS and the 9100 just keeps running with no problems (at least until the UPS battery gets too low).  My advice - skip the 9000 and pay the extra $50 for the 9100.

What power supply do you suggest I purchase to replace the existing one in my XPS 9000?