So… I am trying to expand my farm and come to power limitations on ATX Power Supplies.
The main issue are the 5 Volts. Solution: Power the drives from 12 volt GPU Connector with a dc/dc 5v converter attached.
I have found great resources in https://chiaforum.com/t/scalable-diy-sata-jbod-will-store-over-250-disks/ but there are still uncertainities:
Connector Diagram
Max amount of drives per cable
Ratings:
- The whole cable (8 pin) according to specs is rated for max 150 Watts (~15 HDD’s)
- A single pin is rated for max 8A (96W, ~9 HDDs)
Assumptions:
- my corsair psu has special 1x 8 pin → 2x 8 pin y cables and runs an RTX 3080 fine on it.
→ cable can be used for 300 watts? (2 plugs with each 15 drives connected) - Given that the cable has 3 12v pins and is rated for 150W
→ It seems reasonable to connect 3 * 5 disks to one 6/8 pin plug
→ 5v 10A DC/DC converter should be plenty strong for 5 Disks
Sense Pins
I have some confusion with the sense pins.
Will the PSU just push power through or do I have to do something with the sense pin? For example, In 24 pin ATX plug, pin 14/15 can be connected in order to power on the psu.
Are my assumptions correct so far and/or do you have suggestions/ideas?