M4 SATA hat power limit

[khrubby]

From the spec page of the SATA hat, I read:

(A 12V/2A power can drive one 3.5" hard disk or four 2.5" hard disks. To drive four 3.5" hard disks a 12V/5A power is needed)

I'm planning to connect up to 4x 3.5" drives, and I'll use a separate PSU to deliver enough 12V. However, I can't see anywhere whether 5A will fry the SATA hat. Can anyone confirm if I can power 4x 3.5" drives using the 4-pin SATA PWR connector on the hat? Or should I power the drives separately, and only use the hat for the SATA connections?

[khrubby]

I sent an email to the tech support, and got this answer:

The SATA power connector can output 5V/4A and 12V/4A, and will not be overloaded in this range.

With a typical hard drive requiring <1A during regular operations, this should be fine. There might be a problem with current draw during startup, but I'm hoping that this will be a short enough peak that it doesn't damage the chip.

[ayaromenok]

3.5" HDD can have very different power requirements - and difference between HDD with 1 and 7 platters (and with 1 or 2 actuators, like some 14GB+) can be few times - so it's no general solution.

http://wiki.friendlyarm.com/wiki/index. ... 4_SATA_HAT says exactly about 12V/4A and 5V/4A in scheme

I believe, that you can connect power directly to HDD (since same ground is critical - it's a good idea to use the same power supply for all) and start\stop HDDs the via SATA commands.

[khrubby]

3.5" HDD can have very different power requirements - and difference between HDD with 1 and 7 platters (and with 1 or 2 actuators, like some 14GB+) can be few times - so it's no general solution.

http://wiki.friendlyarm.com/wiki/index. ... 4_SATA_HAT says exactly about 12V/4A and 5V/4A in scheme

I believe, that you can connect power directly to HDD (since same ground is critical - it's a good idea to use the same power supply for all) and start\stop HDDs the via SATA commands.

Thanks for the reply! I checked the wiki page quickly, but didn't think to look closer at the schematic. I'm probably going to start with 1-2 drives, and see if I can find any power specs for the drives I have before trying with 3-4 of them.