Windows Won't Boot - Too many drives connected to PSU

[holygamer]

Hi, I have the 520W Seasonic Platinum SS-520FL2 Power Supply. Basically Windows isn't booting when I have several drives connected to my power supply.

I have a 6 pin to 4 Sata power cable connected to the PSU. I have 4 8TB hard drives connected to that.

I have another 6 pin to 4 Sata power cable connected to the PSU. I have 3 8TB hard drives connected to that.

I have another 6 pin to 4 Sata power cable connected to the PSU. I have a data SSD drive, SSD C Drive and 2 Bluray Writers connected to that. All those drives are connected to the motherboard NOT the sata card.

I have the following items:
Gigabyte GA-Z77X-UD4H motherboard
8GB Ram
Basic Graphics Card
Intel Core i7 2700K CPU.
8 Port Supermicro SAS/SATA Card. This adds 8 SATA III ports

I used a power reader and all the above is using under 200 watts which is well under the 520W the power supply can manage. So why won't Windows boot when I have all the above drives connected to the power supply?

One of the cables connected to the PSU has a SSD Data drive, SSD C Drive and 2 Bluray writers. If I disconnect all except the C drive, Windows will still NOT boot!
I then unplugged 1 of the 8TB hard drives and it booted. Bizarre.

OR with everything connected, if I disconnect 2 8TB hard drives then it will boot. OR if I disconnect 1 Bluray drive and 1 8TB drive then it will boot. The booting problem happens regardless of whether the CPU is overclocked or not. What's bizarre is that my PC was working fine for days with everything connected. I then needed to restart Windows and it wouldn't boot until I disconnected some drives.

Please help. What am I doing wrong?

 

[holygamer]

Yes the C drive is set as the boot drive. Each 8TB drive only uses 7 watts. Total of 28 watts per socket plugged into PSU.

I've got 2 LG BH10LS38.AUAR Bluray writers and 2 SSDs connected to one socket of the PSU. I don't know how many watts the writers use as it doesn't say in the manual. SSDs only use 2 watts each.

Don't know what you mean by rails? You said the 5v rail outputs 100w max. All my drives are connected to the peripheral sockets. Are all those sockets combined one rail? Or is each socket a rail?

 

[holygamer]

Turns out I need to change "Hard Drive BBS Priorities" motherboard setting to have C Drive 1st. Now Windows boots with 7 8TB hard drives, 2 SSDs and 2 Bluray drives!

What exactly does BBS mean? I never even thought to change that setting since boot order already had C drive first then the Bluray drives.