USB Drives Disconnecting

[jrgray93]

Hey, just wanted to share my experience with some drive disconnecting issues I have been having.

I have been using two external drives for rips for years. They are UH12NS40s and were connected via Vantec CB-ST00U3 powered (12v 2a) USB / SATA adapters, plugged into a powered USB hub. They are using patched firmware 1.02.

I recently bumped it to four drives by picking up two more CB-ST00U3 adapters and two WH14NS40 drives. Around this time, I started having problems with drives disconnecting when they would spin up upon opening MakeMKV. Unfortunately, a LOT of my setup changed around the same time, including a new motherboard and CPU, new power strip, different outlet, etc. The WH14 drives would disconnect more often than the UH12s, so I assumed they had problems and may have been causing the old drives to disconnect as well. I started troubleshooting from many different angles.

• First, I patched the firmware on the new drives. This made no difference.
• I tried a different USB hub. New and old were powered. No change.
• I plugged into individual USB controllers per device instead of using a hub. No change.
• I tried using only 1-2 drives at a time. No change, but this is when I noticed the older drives were less prone to disconnecting, and that they actually were disconnecting, rather than just the new ones.
• I tried a different computer entirely. No change.
• I tried older versions of MakeMKV, thinking a software change may be the culprit. No change.
• I bought a UGREEN USB / SATA adapter and tried it. No change. Noted this has a 12v 2a power adapter as well.
• I tried bumping the USB hub from 12v 2a to 12v 5a with an adjustable universal power supply. No change.
• I tried bumping the individual drive USB / SATA adapter from 12v 2a to 12v 5a. This resolved the issue.

It would appear these USB / SATA adapters are so borderline underpowered, they worked fine for me for years on the lower powered drives. Something changed in my setup that I am guessing got them slightly less juice, so they started disconnecting. The new drives appear to require more power, and consequently disconnect easier.

TL;DR: 12v 2a may not be enough for an optical drive, even if the adapter manufacturers seem to think so. If you have problems with USB drives disconnecting, power is very likely the problem. Try the free steps first. Swap USB ports, hubs, etc. Failing that, a 12v 5a 5.5mm x 2.5mm barrel power supply (compatible with the UGREEN and Vantec adapters) costs around $10 USD. There are other, cheaper solutions, assuming you have the right stuff lying around. For example, I could use SATA male to female adapters and run an old ATX power supply with a shorted startup pin. The bricks are just cleaner. If these adapters shipped with even a 2.5a power supply, I probably never would have had this problem...

[Woodstock]

Usually USB-powered drives start to "die" when they go fast, because they pull more than a standard USB port can supply. They pull more than 1 amp at 5v, which causes the voltage to drop, and the drive to shut down. Using multiple drives just complicates things. Feeding "just" with computer power, USB 2.0 doesn't really work that well on multiple drives.

Having not used the Vantec units personally, I don't know how much power they give on their normal adapters. They may just get lazy about full power with "just" a 2amp supply. Those adapters are may not feed the full 2 amps to the 5v side, figuring you need more on the 12v side. But the drives don't even pull from the 12v power... But the 5 amp supply works for full speed.

[jrgray93]

Update to this:

Adding 5a power supplies worked. No more disconnects.

[jrgray93]

Just wanted to necro this to add some information that recently occurred to me...

My drives worked fine for a while with the 2a power bricks. It appears the power was so close to the threshold of failure that minor changes caused the failure. This started happening at the time of year where we don't have the AC on yet but it is still getting warmer outside. The room in which these drives were running doesn't have good ventilation and was at about 20°F higher than usual. That degree of temperature difference can cause up to about a 10% difference in power output. Coupled with the addition of two new drives producing heat in close proximity, it stands to reason that the heat was a factor in pushing them over the failure threshold.

Tl;dr, keep your drives cool and consider higher amperage power supplies if you're using external adapters.