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PSU: Am i right about this?

newtekie1

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Nope. It's easier to break it down by what uses which rails because some things use more than one rail. So it goes:

CPU = 12v
HDD/SSD = 12v + 5v
GPU = 12v

The +5vsb rail is used to continue to send 5v power to devices that aren't turned off when the computer is in standby(the sb stands for standby).

In modern desktop computers, almost everything runs off the 12v rail.
 
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GameplaysFan

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Nope. It's easier to break it down by what uses which rails because some things use more than one rail. So it goes:

CPU = 12v
HDD/SSD = 12v + 5v
GPU = 12v

The +5vsb rail is used to continue to send 5v power to devices that aren't turned off when the computer is in standby(the sb stands for standby).

In modern desktop computers, almost everything runs off the 12v rail.
i need to find the cpu vin and vout, i have the amperage in real time, i want to do a calc

(+cpuvin -cpuvout ) * A
 
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i need to find the cpu vin and vout, i have the amperage in real time, i want to do a calc

(+cpuvin -cpuvout ) * A
the pin out is usually found in the PSU manual.
 
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The CPU goes through a motherboard vrm. You aren't going to measure it independently via a rail if that's what you are thinking.
 
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I'm pretty sure all 12V inputs are tied to the same power rail on most motherboards. So no, you can't isolate CPU load consumption just by measuring a specific input pin. Nowdays the whole 12V rail might used to power everything, from CPU, PCH, RAM, PCIe cards, NIC, USB (especially PD-source), fans, and many more.

You can try to isolate the CPU VRM input and measure the current there for better load isolation, but that would be difficult because on most design it's a power plane instead of trace, and internal layer one at that...
 
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