[SOLVED] My mobo has 8+8, and i want to go to 5.1+ghz on my i-9 9900kf, should i plug both dual 8 pins?

[senseipanda123]

Will the dual 8pins affect anything like in game performance, stability, temps, etc.

 

[MadsModsat]

First of all, it would be useful to know what PSU you currently have or intend to use, and what motherboard. Things like the grapics card or other components which has an significant impact on the required performance of the PSU, would also be helpful to know about.

But for a more general answer, I've seen lots of pepole claiming, that even for the 9900K, one 8-pin 12V EPS connector should be sufficient, even for keeping very high overclocks stable, if the motherboard is of high quality and the VRM design is capable of handling the increased power draw, and is also able to disssapate the large amount of heat generated, to avoid potential VRM thermal throttling reducing CPU performance.
The extra 4-pin, or as in your case the extra 8-pin, is supposedly more important for supplying extra power for multi-GPU purposes, and of course also partially for increased stability.

I have not personally tested both types of setup, but it is certainly something which is frequently discused online. Some agree while others don't.

But considering the way you ask the question in the thread title, it sounds to me like your PSU has two 8-pin 12v EPS connectors, and if that's the case, I would personally use both. I can't see any downsides to it, and if it is actually able to provide additional overclocking stability, why not connect both 8-pins, since overclocking is important to you?

But if you currently don't have a PSU with dual 8-pin 12V EPS connectors, or don't have the cables needed, you should still be able to work your way towards the planned overclock, and see if it will work for you.

If you feel like you are being held back by a lack of sufficient or stable power, you can upgrade to a suitable PSU of good quality with the required connectors

My own motherboard has an 8-pin with an additional 4-pin 12v EPS connector. Eventhough I do not overlcock, I have both the 8-pin and the 4-pin connected, since I have the cables and plenty of outputs available on the PSU.

I'm sure it is not really necesseary, but since I don't see any real downsides, I've personally decided to use both cables anyway.

 

[senseipanda123]

I have the Aorus Master z390, Corsair rm850x psu, asus strix rtx 2080ti.

 

[senseipanda123]

The psu comes with seperate 8 pin cpu power connecters, not dual.

 

[MadsModsat]

The psu comes with seperate 8 pin cpu power connecters, not dual.

What do you mean by that?

According to the manual (page 6), your power supply comes with two seperate cables with 4+4-pin 12v EPS connectors, which would be the ones you need for the two 8-pin connectors on your motherboard

 

[mdd1963]

two each 8 pin connectors would/could be referred to as 'dual', or 'two' or 'a pair of'...

(I'd be surprised if using a pair of ATX12V in results in any increased headroom above 5 GHz, however; good luck if it does, of course!)

 

[MadsModsat]

two each 8 pin connectors would/could be referred to as 'dual', or 'two' or 'a pair of'..

That much I did understand, and since the exact make and model of the PSU is known, it is easy to look up the modular cable kit included, and that includes two seperate cables both with 4+4-pin (8-pin) connectors.... which you say would be described by some as "dual", since there are two of them, a pair (which I am fully aware of). But that's is exactly the very reason I didn't completely follow the part of OP's message i quoted above, where it is mentioned they are not dual but seperate - which is pretty much the same thing, since two of them are included in the modular cable kit for the PSU?

But despite that, I don't see the importance of wheter the neccessary connectors come in the shape of a single cable, two cables or for that matter even 4 cables with 4-pin connectors each as long as they are correct for the PSU, what matters more in my opinion, is that OP's PSU comes with the connectors neccessary to connect both 8-pin sockets on the motherboard to his PSU, if OP wants to try that configuration, hoping for better overclocking potential.

I personally agree, that the benefits of using both cables are probably not substanciated. I tried to expres that in my initial reply, by mentioning the possibility of a later PSU upgrade, if the overclcoking potential appeared to somehow be restricted by not using both available 8-pin connectors from the start, and the required connectors weren't available on the current PSU. I didn't quite succeed in that, but I gave it a shot.

But on the other hand, if the cables are available, and it doesn't lead to any other problems like cable management, airflow restrictions etc, I don't see any harm in connecting both 8-pin cables regardless if they add stability or not.
I'm sure they are not going to damage anything, and you'd also avoid thinking to yourself if connecting both 8-pins would have been better than just one, when a certain OC is almost achievable, but not quite