Author

Topic: Sucking precious power out of Multi-Rails PSU. (PIC) (Read 1382 times)

legendary
Activity: 4326
Merit: 3519
what is this "brake pedal" you speak of?
there are pros and cons to each.

multi rail: Pro - overcurrent protection on each rail. a short on one string (rail) will shut the PSU down before the string wiring can catch fire.

multi rail: Cons - have to balance the rails

single rail: Pros - no load balance worries. jump start your jeep!

single rail: Cons - fire if something shorts big time.. 100 amps on a single wire = bad news.

BTW internally most all "multi rail" PSUs have one 12v source (which also powers 3.3v and 5v rails), each rail has  overcurrent protection though.



hero member
Activity: 770
Merit: 502
Why not stay away from multi rail psu's? Only buy single rail psu's?
legendary
Activity: 4326
Merit: 3519
what is this "brake pedal" you speak of?
the PSU manual may specify what strings are on what rail.

for example my antec TP 550 new manual (pdf link) tells exactly whats on what.
full member
Activity: 182
Merit: 100
Ah i get it now.

How do you know if the PSU reserves a rail for the CPU? Do you ahve to open it?
donator
Activity: 1731
Merit: 1008
Stripping the insulation ~1 cm and twisting the other wire on it.
full member
Activity: 168
Merit: 100
not sure if i see it right,but you tap the p4 wire?

Using the 2nd 4pin for the CPU is never a requirement unless you plan on going 100w +
(miners use Celerons and 25w cpu of the like.)

I have a few 4pin grabbed from dead PSUs that I sometime plug with a molex to power the CPU.

This way I can use the whole 8pin and use them as PCI-e ,,, I am now to use a tool to make custom pci-e without any tampering to the PSU. (warranty safe)

I understand that, but how did you use your 8pin EPS rail? you tap your PCI-E on it or did you use an adapter 8pin EPS -> PCI-E connector.
donator
Activity: 1731
Merit: 1008
not sure if i see it right,but you tap the p4 wire?

Using the 2nd 4pin for the CPU is never a requirement unless you plan on going 100w +
(miners use Celerons and 25w cpu of the like.)

I have a few 4pin grabbed from dead PSUs that I sometime plug with a molex to power the CPU.

This way I can use the whole 8pin and use them as PCI-e ,,, I am now to use a tool to make custom pci-e without any tampering to the PSU. (warranty safe)
full member
Activity: 168
Merit: 100
I can't count the number of time I had to do this.

Reroute the 4pin into PCI-e.

That PSU, PowerColor 500w, dedicate a whole 18amp for the CPU


https://i.imgur.com/1HvAd.jpg
not sure if i see it right,but you tap the p4 wire?
legendary
Activity: 812
Merit: 1002
I dont get it, what's wrong with an adaptor that you get when you buy the video card?
that adapter that comes with the video card pulls power from a peripheral cable, which is probably a different power rail than the CPU power rail on a multi rail PSU. you want to take advantage of the CPU's rail as well since the CPU (for dedicated miners) shouldn't be pulling that much power.
full member
Activity: 182
Merit: 100
I dont get it, what's wrong with an adaptor that you get when you buy the video card?
donator
Activity: 1731
Merit: 1008
Well ,,,
Black = ground
Yellow = 12v
legendary
Activity: 812
Merit: 1002
this was something i was thinking about doing, but wasn't sure if it's safe for the PSU or video card, and i also didn't know the pin assignments. can you show which CPU cable pins to go into which pci-e cable pins?
donator
Activity: 1731
Merit: 1008
I can't count the number of time I had to do this.

Reroute the 4pin into PCI-e.

That PSU, PowerColor 500w, dedicate a whole 18amp for the CPU


https://i.imgur.com/1HvAd.jpg
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