Solved! What PSU with at least 142W combined on 3.3v/5v rails would you recommend?

Coyle

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May 15, 2020
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My child's XPS 8300 PSU finally died & according to someone over at Dell forums the PSU needs to have a min of 142W combined on the 3.3v/5v rails (I have a CX650 that is 130W combined?) They suggest an EVGA 850BQ which does have 160W combined (also the 700BR which has 150W but I can get the 850BQ overnight.) Is that a good PSU? When I was building my pc last year think I recall reading that was not good (ended up getting the CX650 & also a Super Flower Leadex iii 550w that I put in the build & kept the CX650 for a backup as PSU's were hard to come by then.) Is there a better PSU than the EVGA 850BQ/700BR around same price, that has the min 142W combined 3.3v/5v rails? Or do you think I could use the CX650 with it's 130W combined? There's nothing but the single stock HD & a usb 2.0 wifi adapter.
Standard size around 5.51 x 5.91 x 3.35 inches.

This is what was said:

There are 4 slots or more on dell motherboards and EACH Slot uses 3 AMPS or 10W of power for the 3.3v rails USB ports use 2.5 to 5W per port on the 5v rails AND thats not the only place that these rails are used. SATA Drive ports have 5 wires because 3.3v is also available on those ports so if you are using mechanical drives you are using 3.3v, 5v, 12v power for each hard drive at 12W to 25W PER Drive.
The point is that combined output on the 5VSB rails must be 3 AMPS minimum and the 3.3v Rails must be 142W Minimum.
 
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VirtualLarry

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Aug 25, 2001
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I wouldn't worry about that so much. That's only if you max out the power on EVERY slot and SATA port.

I would worry more if that's a Dell proprietary ATX pinout versus standard ATX.
 
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jonnyGURU

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someone over at Dell forums the PSU needs to have a min of 142W combined on the 3.3v/5v rails
What is their logic for this. This makes absolutely no sense to me.

Are you using the Corsair now and having issues?

There are 4 slots or more on dell motherboards and EACH Slot uses 3 AMPS or 10W of power for the 3.3v rails USB ports use 2.5 to 5W per port on the 5v rails AND thats not the only place that these rails are used. SATA Drive ports have 5 wires because 3.3v is also available on those ports so if you are using mechanical drives you are using 3.3v, 5v, 12v power for each hard drive at 12W to 25W PER Drive.
The point is that combined output on the 5VSB rails must be 3 AMPS minimum and the 3.3v Rails must be 142W Minimum.
This guy? https://www.dell.com/community/XPS-Desktops/XPS-8300-PSU-replacement/td-p/7324679

Forget about maximum potential power. What is YOUR scenario?

You're using all four slots? You're using five drives?

I have NEVER seen a desktop PC need so much power on the +3.3V and +5V. What's being defined here is a fully populated system with everything being run at full power at the same time, which simply never happens.
 
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