PSU spec lable meaning

[kerskjee]

I have a 350W psu and i was wondering what the meaning of the 3 different 12v labels are.

On the label it says:
12v1 - 16a
12v2 - 16a
12v3 - 16a
5vsb - 2a

So seeing as all 3 12v "rails" are 16a, its safe to assume that it is a single 12v rail, right? But why then is it labeled like that, what is the significance of it?

 

[RememberThe5th]

Dunno, probably marketing. Which brand model ?
5V sb 2A? 😵 My vs 550 has 1A

 

[orionfotl]

No, it means it has three +12V rails. (Of course the label may lie, and it may actually have just a single +12V rail).

Those specifications mean that one group of cables is limited to 16A, another group of cables has the same limit, and a third group of cables has the same limit.
For example, The CPU cable may be on the first rail, so you can draw up to 192W through it. The 24pin, SATA and Peripheral cables may be on the 2nd rail, so you can draw up to 192W from all of them. And then the PCI-express cables may use the third rail, so you can draw up to 192W from them.

Of course we can't know for sure what cables are assigned to what rail, because you didn't tell us what PSU you have.

Dunno, probably marketing. Which brand model ?
5V sb 2A? 😵 My vs 550 has 1A

Your Corsair VS550 has a 2.5A standby rail.

 

[RememberThe5th]

woops remembered the ms one...
Sure the 16A per cable is a lie since its 350W.
Usually they write down for all groups max rated XXXw like on my delta psu.

 

[kerskjee]

No, it means it has three +12V rails. (Of course the label may lie, and it may actually have just a single +12V rail).

Those specifications mean that one group of cables is limited to 16A, another group of cables has the same limit, and a third group of cables has the same limit.
For example, The CPU cable may be on the first rail, so you can draw up to 192W through it. The 24pin, SATA and Peripheral cables may be on the 2nd rail, so you can draw up to 192W from all of them. And then the PCI-express cables may use the third rail, so you can draw up to 192W from them.

Of course we can't know for sure what cables are assigned to what rail, because you didn't tell us what PSU you have.

Dunno, probably marketing. Which brand model ?
5V sb 2A? 😵 My vs 550 has 1A

Your Corsair VS550 has a 2.5A standby rail.

The PSU is not a retail one (FSP350-40UGBBD), it came in my MSI Nightblade MI2C. Is it possible to derive some sort of info on the quality of the PSU form the labeling?

PS: under the 3 12v rails it says 350w max, and then under that again (under all 3 12v rails and the 5vsb) it says 350w max again.

 

[orionfotl]

The fact that the power it has available for the +12V voltage is the same as total power altogether (350W) means that it should use DC-DC converters, which can hold correct voltages much better than lower quality power supplies.

We don't know if it uses durable components and exactly how good it performs in terms of providing clean power, you'd need a teardown and testing for that. The label also doesn't say which cables use which rail, you can only check it by testing or by opening the power supply.

Regardless, if it came with an MSI case/computer, then I assume the power distribution won't be a problem.

 

[kerskjee]

Awesome, thanks for all the info