More info about your mobo/other hardware would be helpful..When you unplug or turn off the PSU, the CMOS battery is the only thing keeping the BIOS from defaulting..Sounds like maybe the CMOS battery is dead/dying and the BIOS is reconfiguring itself after a total power loss and rebooting..I'd put a new CMOS battery in and go from there.

Hey guys, 
 
Thanks for the replies, and yes, I should have posted that from the start, sorry. Here we go:

• Intel Core i7-5820K - no overclock
• ASUS X99-A - with latest bios
• 2x 8GB Crucial DDR4 Ballistix 2400MHz DDR4 XMP PC4-19200
• EVGA SuperNOVA 750 G2 PSU
• EVGA GeForce GTX 970 SSC ACX 2.0

All new stuff, built it 2 weeks ago.
 

bob16314When you unplug or turn off the PSU, the CMOS battery is the only thing keeping the BIOS from defaulting..Sounds like maybe the CMOS battery is dead/dying and the BIOS is reconfiguring itself after a total power loss and rebooting..I'd put a new CMOS battery in and go from there.

 
Don't think its that, all my custom settings in BIOS are still there after it have been unplugged for a while
 
I've having RAM problems though, original ran it with 3 sticks of 8GB ram, but computer keept freezing all the time, no BSODs, and I ran Memtest64 over night and it passed all test twice without errors. But someone suggested that my MOBO required ram in pairs, so took one out and the freezes almost stopped although not completely. And now I'm running through Memtest64 stick for stick, have only done one so far as I have to do it over night but that one failed all the hammering tests generating a lots of errors (2243). No errors in any of the other tests.
 
Can these reboots be related to that? If so, why only after power have been unplugged? Or if these reboots are caused my faulty PSU, can that then give problems with the RAM?
 
Sorry if this turned more to general troubleshooting rather then PSU related.

Yes, AI suit is uninstalled, or I never installed it after last clean windows install. Although did a auto tuning before that, can that have messed with the ram settings and caused the freezes maybe?
 
Haven't touched the Mem(OK) button and no red LED lit near it! ...btw, that button resets the ram to "safe" settings right?
 
Although this reboot issue have been from day one when putting the computer toghether, the freezes started a few days later.
 
 

Probably completely unrelated, but... doesn't X99 use quad-channel memory (same as X79)? If so, you really should be running four sticks, and I think it's probably recommended that you use a matched set, as opposed to combining multiples.
 
As for the other, I've had older ASUS motherboards do the exact same thing you're seeing with the initial reboot. It only gets as far as the boot logo and then reboots-- correct? If memory serves, both my P5W-DH Deluxe and P5E did the same thing the first time they were powered up after disconnecting from the mains, or flipping the toggle on the power supply. Mine would fire up, then shut off, and power back up on their own a couple seconds later. After that, everything was normal (including both cold and warm boots) until I disconnected the power cable again. Seemed weird, but it also seemed like it was intentional since the boards would do it every time, without fail.
 
For the record, though, my most recent motherboards (Rampage III Formula and Rampage IV Formula) have never done it. I think your issues are probably memory-related since you've already had one of the sticks fail with Memtest.

fatherofcharlie
Says it runs Quad Inline Memory...so yes? But recommended configurations in the manual is, 1, 2, 4, 6 and 8 sticks.
 
...according to Crucial, the sticks I have should be compatible with the ASUS X99-A even thought they are not on Asus list. 
 
Actually never gets to the boot logo, it takes about 1,5-2 seconds before it reboots and that is before the boot logo comes up.

I could be wrong about them reaching the logo before they powered down and rebooted... it's been a while (at least 4+ years since I actively used the P5E, and even longer with the P5W). But it sounds like the same behavior: power on, LEDs light up and fans spin up, board goes dark as it briefly shuts down, then the LEDs and fans come back to life as it successfully boots. And any boot/reboot after that was normal until the next time I yanked the power cord.
 
And yes, the board should work with those memory configurations listed in the manual, but quad-channel is how it's meant to be used (either four single sticks, or four pairs of two). I was just mentioning that since you said you started out with three sticks. I'm used to only using four sticks in quad channel since that's all that my current board (the R4F) will accommodate. (The Formula is basically a cut-down Rampage IV Extreme, and one of the cuts they made was eliminating four of the memory slots. I often forget that most X79 and X99 boards probably have four banks of two since mine only has four single banks. Sorry!)

fatherofcharlie
Hi Guys, 
 
I have a EVGA SuperNOVA 750 G2 PSU and it seems to work fine. But every time I have had the cord unplugged from and first time booting up the computer shuts itself down after 2 seconds then reboots and everything is normal. It only happens first time after I have had the cord unplugged, all other times no-matter if it is a cold start or a restart, from Windows or BIOS, it never happens.
 
Thoughts on this behavior?
 
Thanks in advance!

It's a specific function of  EVGA and ASUS motherboard it seems
I've had the same issues with both and even a guy on JayTwoCents on youtube has had it

fatherofcharlie
Ok, thanks!
 
So totally normal and intentional then?

For the PSU, I don't know but I do think it is for their motherboards
If you have EVGA or ASUS then it's probably a normal thing

deadite_9
For the record, though, my most recent motherboards (Rampage III Formula and Rampage IV Formula) have never done it.

I stand corrected... the R4F most certainly does do this (and I'm sure now that the R3F did as well). I suppose I just never noticed it before. But it definitely seems to be an ASUS "feature," and not a problem with the board.

It's normal happened to me too with a different psu.
Currently I moved for ax1200 to ax1500i corsair psu and it doesn't do this.
However have you tested sleep and wake settings? I mean have you tested putting the system to sleep and waking it with a mouse movement or hitting a key on the keyboard? And if you do, does it still do the same? Or does it never come out of it?