Multi Rail PSU Question

box o rocks

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In this multi-rail PSU there are 4 x +12v rails. I kinda figure that +12VCPU is the CPU and +12VG is the 6-pin for the graphics card. But what do you suppose the +12VS and +12VB rails are?

And why the heck are there separate "rails" anyhow?

And since the +12V rails are safe up to 400W, can the PSU be used to run a RX-580?
 
Solution
Just additional 12V rails. Most multi-rail supplies still use a common source. The idea is that each rail has independent over current protection. So if you exceed the 12.5A on +12VG it will shut off, or the 18A on any of the other rails.

As for running an RX-580, not so much, but it really depends on the power draw of the rest of the system. If +12VG is really for the graphics, then at most it should power dual 6-pin or a single 8-pin PCIe power connector (150W). That is a 185W card, potentially much more with a little overclocking. So it will pull power from the slot as well. The rest of your system should be under 100W in that situation for it to be a long term solution.

Ideally you want a power supply to be between 50-80% of its...

Eximo

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Just additional 12V rails. Most multi-rail supplies still use a common source. The idea is that each rail has independent over current protection. So if you exceed the 12.5A on +12VG it will shut off, or the 18A on any of the other rails.

As for running an RX-580, not so much, but it really depends on the power draw of the rest of the system. If +12VG is really for the graphics, then at most it should power dual 6-pin or a single 8-pin PCIe power connector (150W). That is a 185W card, potentially much more with a little overclocking. So it will pull power from the slot as well. The rest of your system should be under 100W in that situation for it to be a long term solution.

Ideally you want a power supply to be between 50-80% of its load. So for something like an RX580 and a typical ~95W CPU, then a 550W power supply is closer to the correct rating.
 
Solution

box o rocks

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Let me follow up on that, if I may. In lieu of the higher wattage RX-580, would a GTX 1060 6GB be doable with that PSU? Zotac recommends a 400W with 1x6 pin.
 

Eximo

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It would certainly be better, but I still wouldn't want to do any lengthy gaming sessions with a Delta power supply. And it still depends on the rest of the system's power draw.

Rule #1 when building computers. Don't cheap out on the power supply. If it fails badly it can cost you everything. You also gain a lot of system stability by using a high quality supply. Less work for the various VRMs in the system also increases longevity.

 

box o rocks

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I'm not building a computer, this is a HP Z-something Workstation with the factory-supplied PSU.
 

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I know, Delta is the primary supplier to HP and Dell. Typically not power supplies I would trust running gaming loads hour after hour. They are sized for the equipment they are sold with. When you start expanding beyond that you are typically exceeding the envelope those PSUs were selected for.

It will almost certainly work, but the components inside the PSU will heat up more than normal, meaning the PSU fan will have to run faster. Either the fan will fail or one of the main PSU components will fail eventually. PSUs main capacitors also degrade over time, so if this system is already a few years old it won't be delivering its maximum output anymore. Whereas you can go out and spend $60-80 on a PSU that comes with a 7-10 year warranty and will last that long.