Really amazing setup. What length of sata cables are you using? AFAIK the max length of sata cables without any possible signal degradation is 1m. Does using the sata multiplier reset this? i.e. can you attach 1m sata cable to the multiplier input and use 5 1m cables for the sata ouputs?
1 Like
Thank you! I use these 36" cables from the r520 (through an open PCI slot for now, until I need it lol): Amazon.com: 24 Pack 36inch SATA 6Gbps Cable w/Locking Latch (90 Degree to 180 Degree) - Silver, CNE569499: Computers & Accessories
And then I use normal 20-24" SATA cables coming out of the port multipliers. And yes, from what I understand, because the port multipliers are powered and they have their own chip, they “reset” the max length of SATA cables. I certainly haven’t had any issues from them in the last few months!
1 Like
I tried going the usb-sata route, but am currently facing various disconnect issues. My setup -
4 disks with sata-usb adapters in one stack with one cooling fan. all connected to a 4 port hub, which is further connected to another hub. Using a 350W 12v psu to power 16 of these drives
2 Likes
Commercial jbods often include staggered spin-up to avoid sudden power spike when the rig is turned on. I see this feature advertised on 24 bay units.
What’s your experience on that matter with 60 disks?
1 Like
Power distribution is definitely a big problem, and I fought some disconnect issues too - I always traced it back to inadequate power. In fact I just ordered 2 more 1200w server power supplies. They actually only supply up to 900w on 120v. I can power up to 60 drives with it, but I start facing disconnect issues at that point. I’m backing down to power only 50 (or maybe even 40) with a single power supply to make sure it can keep up.
If you have a multi-meter, you might measure your voltages and make sure you are still getting at least 12v and 5v at the connection points!
1 Like
Ugh - currently my experience is “not good” lol. I currently have a very ritualistic startup procedure of manually powering up only so many drives at a time by literally plugging them in. Once all the drives are on, then I can turn on the server. Luckily I rarely have to do this - the server can be rebooted/powered off and the drives can still be left on since they have their own power supply. But yes - if I just try to turn them all on at once, the power supply says “nope” and just shuts off. I’ve already ordered some 20amp 12v switches so I can more easily manually turn on/off 5-10 disks at a time. Hopefully a big enough UPS backup will make it so I rarely (if ever) have to go through this manual startup procedure.
2 Likes
You can get a grounding wire “cheater” similar to https://www.ebay.com/itm/353468816379?chn=ps&mkevt=1&mkcid=28 and clip it to the rack. Only thing is that you’d have to plug it into a wall outlet and not a power strip/surge protector.
Or you can take a grounding wire and mate it to https://www.homedepot.com/p/Leviton-15-Amp-125-Volt-Double-Pole-3-Wire-Grounding-Plug-Black-R50-3W101-00E/205165472 and then only connect the ground pin.
Could you explain this on a lower level? 
How do you connect a 12v output to both a sata cable and a 12to5v converter, and then connect the 5v back into the sata cable?
I have a 1000W power supply with a very unused 12V rail so would love to know how to do this, then I would only need one system to power all my drives.
A traditional ATX PSU will have a 12v and 5v rail to power a hard drive, they both go into the SATA power connector from your PC power supply to your HDD. 12 volts powers the motors and actuators that spins the platters and moves the heads in a HDD. 5V to power the PCB controller etc. This is why HDDs will have a 12V and 5V amperage rating.
With external HDDs like WD Elements or Seagate Expansion drives you won’t have a 5v rail, everything is powered from a 12V mains adapter that you plug into your External HDD. However, on the USB-to-SATA pcb/controller it will have a voltage regulator that will take some of the 12v power and convert it to a separate 5v supply to power the HDD.
Now, if you’re going non-USB and non-ATX and rigging your own janky power supply (like this guy), you’ll need a 12v PSU and connect it to the SATA power connector for the 12v it needs. But you’ll also need to make the 5v. You can do this by connecting another wire from the 12v to a 12v-to-5v converter, this becomes your 5v supply. Connect these to the right pin of a SATA power cable et voila, a powered HDD. All you need to do now is connect a SATA data cable between the HDD and your PC for data.
*Cue the A-Team theme song*
2 Likes
If you were doing just SATA power and Molex power (Molex to SATA converters), all you would really need is a decent PSU, like 800w+ with a power switch on it. Then just jumper the 24 pin motherboard power. You could have as many PSUs as needed doing it that way. If you ever needed to power the system OFF, just flip the PSU switch or unplug it.
I’m sure this dude has his reasons. Whatever they may be.
I’m going with ‘because he’s nuts’, but only because he’s strapping hundreds of HDDs to a wire rack to farm a digital currency with no proven value. Clearly he belongs in the loony bin. 
This actually answered a different question but one I also wanted an answer to, you a psychic?
I see, I was hoping for a way that did not involve jerry-rigging connectors together
Just died from laughing 
1 Like
Interestingly, this thread has been showing up in my Google News feed. Ya made the big time!
2 Likes
Yep, @uChiaFarmer nailed it:
I use one of these per 10 disks: Amazon.com: BANKEE DC 12V 24V to 5V 15A Converter DC Voltage Reducer Regulator Step Down Buck Converter Power Supply Volt Transformer Module (12V/24V to 5V 15A): Electronics
The 12v line from the PS goes into the input terminals. I also put the 12v line from the SATA power connector on these input terminals - a natural splice. Then I put the 5v line of the SATA power connector on the output terminals. Now I have a single line running from the PS, interrupted briefly by a 12v-5v converter, then finally 12v and 5v going into the SATA power connector. Here’s a pic for clarification:
Of course, but have you ever priced a good 800 watt PSU? These refurbed 1200w server PSUs go for $55 on Amazon and they are rock-solid! 
Because money! See above. Although after the additional breakout board, wires and 12-to-5v converter maybe I’m not actually saving any money. 
3 Likes
What I would like to know is, what is this?
I can’t identify it and I was curious. Looks like a 6-pin molex power distribution unit, but I’ve never seen anything like it.
2 Likes
Oh that’s the breakout board, commonly used for GPU mining (hence all the GPU power connectors). Each one of those connectors has 3 12v lines, more than enough for our uses. The board itself also has a “floppy disk” style power input on it that it can use to turn the power supply on from another power supply. Otherwise it has a on/off button and a nice voltage readout.
1 Like
I just sat here admiring this for a few minutes. It’s a surprisingly elegant (and clean) solution, considering how the rest of it looks. 
1 Like
Wow, very impressive.
What’s your typical HDD price per TB for your current rig? <20? 25/TB? It’s definitely a big farm and budget will be a factor how much HDDs you can add.
Yes I have. You can get a Cougar or EVGA or Be Quiet or Phantex 850w and 80+ rated PSU for around $100. You would only ever need 2 of them + some molex to SATA adapters and some SATA splitter cables.
Your converters cost half that price of a PSU, but anyone looking to replicate this could need more than 2 to do it properly and IMO safely. In your picture, the PSUs show 75W. Also, the PSU you linked to is a DELTA/HP server PSU. The cost isn’t worth it at $155 used on Amazon.
Thank you! I use 4tb enterprise drive and I get them for about $10/tb. Actually my last order was about $12/tb including shipping.
For sure! When I ordered 2 of them just earlier this week (Monday I believe) they were $55/each:
I got my first one on eBay for around the same price. It looks like the price probably fluctuates on Amazon depending on stock, but if you keep watch you should find them for less than $60. Also the PSU isn’t 75w, you may have meant the 12v-5v converter? Those are probably overpowered actually, they each can handle 75w of 5v. Each drive takes less than a watt amp of 5v, so plenty of overhead there! One worry I always have with “normal” ATX power supplies is the 5v rail. A lot of them are underpowered for this type of application, so making my own gives me plenty of overhead!
2 Likes