+12V rail selection switch on Corsair HX1000 Platinum 1000W PSU - which to use?

[eeokin]

Hi guys the HX1000 has a switch to select multiple or single:

 

 

Which option do you suggest I use to power my build?

 

• 7950x
• 3080Ti
• 64gb DDR5 memory

[Zando_]

Multiple. 

[mariushm]

I'd say you can leave it on single.  Single just disables an extra protection mechanism.

 

Multi just means the power supply may shut down if it detects the video card or the cpu consuming more than 40A (12x40A = ~ 480w)  through one cable. 

 

The 3080ti  is very unlikely to trigger this protection, but not 100% impossible.

 

[eeokin]

2 minutes ago, mariushm said:

I'd say you can leave it on single.  Single just disables an extra protection mechanism.

 

Multi just means the power supply may shut down if it detects the video card or the cpu consuming more than 40A (12x40A = ~ 480w)  through one cable. 

 

The 3080ti  is very unlikely to trigger this protection, but not 100% impossible.

 

Thank you for your response. Would I be slowing down my components by using multiple? 

[seon123]

2 minutes ago, eeokin said:

Thank you for your response. Would I be slowing down my components by using multiple? 

No. The only difference is that the PSU will shut down if e.g. an SSD tries to pull 800W through the 12V rail, if it's set to multi rail, while single rail mode would happily let that happen. Leave it in multi rail mode, that's how they should ship out anyway. 

[Spotty]

5 minutes ago, eeokin said:

Thank you for your response. Would I be slowing down my components by using multiple? 

No.

With those power supplies Multiple rail mode just means that there is OCP (Over Current Protection) for each of the cables from the power supply. It's set to 40A, which is 480W at 12V, which is pretty unlikely to draw from a single cable under normal conditions. It's like a breaker for your PSU, like in your house if you have too much stuff plugged in to one outlet like a microwave and a toaster running at the same time or an electric heater and a TV plugged in to the same outlet. Setting to single rail mode just disables that 40A limit and lets it deliver as much power as the PSU can over any cable.

I would leave it in multi rail mode and if you have issues with the PC shutting down under load, switch it to single rail mode. Unless you're doing extreme overclocking like LN2 CPU cooling hitting 6GHz it's very unlikely you would ever draw enough power to trip the 40A limit.

Edited September 28, 2022 by Spotty

[eeokin]

Thank you so much guys!!!!!!!!!!