The life span of new/refurbished or used Dell OEM psu is unpredictable. I have owned many original Dell OEM psu. The majority are still working after 9-10 years and a few died.  To be sure of having 3+ year life you can consider non OEM 460w ATX psu from reputable brand name such as EVGA.  Here is one that has 3 year warranty.  Pretty sure EVGA psu lasts much longer than 3 yrs.  It is on sale on Amazon for only $30 now, a good deal.
So my 8910 power supply died last week and I'm searching for a replacement. After looking for days on this board I still can't seem to figure out what to get. Dell doesn't have my information saved and my Xps won't power up, so I don't know the exact specs, but I purchased in 9/2017. It's an i-core 7 with a lower end graphics card (Nvidia 560 or 570) and I use primarily for graphic design, not gaming. Looking to get a  super flower or something halfway decent so it will last me awhile, but want to be sure it will fit and work with my computer.(Currently back online with my old studio running vista and it is so slow) Would this work? [URL]|superflower-_-11 
XPS 8910, PSU upgrade, #12