upgrade T5820's psu to 1400W

8/31 Edit:  I got mixed up.  OP has T7820.

I have a Dell Precision 7820 tower with dual CPUs and a 300W video card, and I plan to upgrade it to dual Intel Xeon 6258R at 205W TDP each. Will my 950W power supply handle this upgrade?

@bradthetechnut​ 

 Thank you, I found ads on eBay for a 1400W power supply for a Dell Precision 7820. Can I purchase it and replace its original 950W power supply?

I meant to say in the accepted answer that the 950w PSU should be enough.

I edited my first post after your first post.  I got mixed up between the T7820 and T5820.

As for upgrading to a 1400w PSU, it's not a bad idea.  However, Dell didn't validate any 1400w PSU's for the 7820.  As for the ads, I and others can't tell you if it'll work or not without a specific link to the item.

Hi @Chino de Oro - Are there any 1400w PSU's that will work in the T7820 and would the power distribution board have to be changed?

Thanks Brad for valuing my opinion and input.

The 1400w PSU from T7920 can not be fitted into the T7820.  The PSU housing of T7820 has a groove on one of top corner that would allow only 950w PSU with the same keyed indented corner to fit in.  

Even with the chassis modification to take 1400w PSU, the power distribution board is much different between T7920 and T7820.  The T7820 has fans headers and temps sensors on motherboard whereas the T7920 has them on power distribution board.

The power rail drops also are different.  In the T7920, the extra power from 1400w being routed to support up to 3 x 300w graphics cards and additional flexbay, not the processors.

@Chino de Oro​ 

Thanks for the info.  :)

Thanks for this valuable information. I have another problem. I read on some websites that some Dell 7820 motherboards do not support 2nd generation Cascade Lake processors. Does my motherboard (05wnj2) support 2nd generation Cascade Lake processors?

@Chino de Oro​ 

Hi, Thanks for the clarification, but as far as I know, the power supply shown in the advertisements is not the same as the power supply for the 9720 workstation. However, it can be used for both workstations 7820 and 7920. for example you can see this site web.
https://parts.metservers.com/h1400ef-00-dell-1400w-power-supply-psu-precision-t7820-t7920-tower-server

I couldn't find a supported list of CPU's in Dell doctrine, so check out Precision 7820 userbenchmark.

I almost forgot got your question is MB specific.  I couldn't find an answer on if 05wnj2 can't support requested CPU.  If you try it, you might just have to make sure CPU comes with something for a return policy.