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?

[jim]

It's not just a question of total power draw, it's a question of rails.

Your PSU will be designed to provide most of its power on the 12V rail, but that's not where the drives are drawing from. I can't remember which rail SATA draws from, but you might well be overloading it. If you can find out the answer to that, then work out roughly what your drives are drawing, then find the spec sheet and see what the max wattage of that particular rail is, you'll see if you're pushing it too hard.

Of course, it might be something else entirely, like a dodgy cable or a dodgy drive that when disconnected allows things to work, but you certainly could be pushing it too hard. Especially if after a while it's started to wear out a bit.

[holygamer]

I can't find anything in the manual about what you said. Drives are all new and so are the cables.

I think what I might do is get an SSD PCIe card that way Windows will always boot and I can avoid this problem.

[jim]

I've just had a go at running the numbers, and it seems that typically a drive might draw 0.5-1A from the 5V rail.

Since you've got 10, that's worst case scenario 10A. And your PSU can push 20A on the 5V rail.

So that suggests it's not the issue.

Short of doing some further testing with another PSU or molex -> sata converters I'm really not sure. The only thing that does strike me is that the PSU says it comes with 6 SATA connectors, so not sure how you've ended up with 10.

[spolsh]

Hmmm ... seems Seagates Archive 8tb disks (don't know about other models / brands) has a 2 A start up draw from the datasheets on their website. I think you might have been right on it overloading the rail.

[kalniel]

Hmmm ... seems Seagates Archive 8tb disks (don't know about other models / brands) has a 2 A start up draw from the datasheets on their website. I think you might have been right on it overloading the rail.

If it's that, then you can just stagger the spin ups in BIOS.