help First time builder+poster needing assistance with PSU Cables

[Diane_Abbott]

Hello, im new here.

Preamble:

I have recently purchased a new pc and I have been building it over the course of the last couple of months and I am very much stuck when it comes to which power cables I need to use where. I have looked at the PSU manual and the mono manual, and I have googled persistantly to seemingly no avail so I have come here as I am told this is the be-all-and-end-all of pc building help.

 

Problems:

I have two issues (parts list at end). Firstly when connecting my PSU to my Motherboard I have a 20+4 pin connector on my mobo which fits one end of the PSU cable but on the other end of that cable I have a 24+4 pin connection and I have no idea what to do with the extra 4 pins. There is an extra 4 pin socket on the PSU which is labelled motherboard but idk if that is needed for my mobo as I can't find any info online and I am worried that if I plug in that cable and power the system on it will burn out my motherboard as there is too much power. 

Secondly my mobo has two sockets for the CPU power, one 8 pin (labled EATX12V_1 in manual) and one 4 pin (tabled EATX12V_2 in manual). I have connected them up using two 8pin to 4+4pin cables. both of the 8 pin ends are in the PSU and I have plugged one whole 4+4 pin cable into the 8pin on the mobo and for the 4pin socket I have plugged in half of the other 4+4 and left the extra 4 pin on the cable dangling. Is this correct? I have no cable on my psu that goes into only a 4 pin connection so I assumed that this was the only choice I had. I have read online that the sole 4 pin CPU power connection is not necessary but I don't know if the information that I read relates to my exact setup.

 

PC Specs:

CPU: Ryzen 7 5800x

MOBO: ASUS ROG Strix b550-a gaming

PSU: Silverstone ST85F-GS 850w V2.0

RAM: Kingston Hyper-x Predator 3600mhz 2x8gb

GPU: GTX 980 (waiting to upgrade to 3080 at some pint in the future)

Case: Thermatake S300 TG Snow Edition

 

 

Any help would be greatly appreciated. If I am in the wrong place please could you tell me where might be more appropriate?

[WhitetailAni]

1 minute ago, Diane_Abbott said:

Firstly when connecting my PSU to my Motherboard I have a 20+4 pin connector on my mobo which fits one end of the PSU cable but on the other end of that cable I have a 24+4 pin connection and I have no idea what to do with the extra 4 pins. There is an extra 4 pin socket on the PSU which is labelled motherboard but idk if that is needed for my mobo as I can't find any info online and I am worried that if I plug in that cable and power the system on it will burn out my motherboard as there is too much power.

Plug the 4-pin in as well. It won't burn it out - power is pull, not push.

2 minutes ago, Diane_Abbott said:

Secondly my mobo has two sockets for the CPU power, one 8 pin (labled EATX12V_1 in manual) and one 4 pin (tabled EATX12V_2 in manual). I have connected them up using two 8pin to 4+4pin cables. both of the 8 pin ends are in the PSU and I have plugged one whole 4+4 pin cable into the 8pin on the mobo and for the 4pin socket I have plugged in half of the other 4+4 and left the extra 4 pin on the cable dangling. Is this correct?

This is fine, though you don't need the extra 4-pin.

[Spotty]

8 hours ago, Diane_Abbott said:

Firstly when connecting my PSU to my Motherboard I have a 20+4 pin connector on my mobo which fits one end of the PSU cable but on the other end of that cable I have a 24+4 pin connection and I have no idea what to do with the extra 4 pins. There is an extra 4 pin socket on the PSU which is labelled motherboard but idk if that is needed for my mobo

If there's a total of 28 pins on the power supply side it means the PSU has sense wires on the 24pin cable. Plug it in.

 

8 hours ago, Diane_Abbott said:

Secondly my mobo has two sockets for the CPU power, one 8 pin (labled EATX12V_1 in manual) and one 4 pin (tabled EATX12V_2 in manual). I have connected them up using two 8pin to 4+4pin cables. both of the 8 pin ends are in the PSU and I have plugged one whole 4+4 pin cable into the 8pin on the mobo and for the 4pin socket I have plugged in half of the other 4+4 and left the extra 4 pin on the cable dangling. Is this correct?

Yes, that's correct.