Anyone use a USB 3.0 enclosure + SSD drive as boot disk for iMac ?

[CuriousMike]

My daughter has a 2013 iMac 21.5 - it came with an internal 1TB spinner.
The disk makes it godawful slow.

I watched a youtube video where a guy purchased a particular usb3.0 enclosure and stuck an SSD drive in it and used that as a bootdrive for the iMac.

I followed the procedure and it seemed to work smoothly.

Until a few days later my daughter mentioned the iMac froze and its never done that before... she rebooted, and it's fine.

She's had it installed for a few weeks, and its locking up once every 3-4 days - it would never do this.

For now, I've had her unplug the drive and just boot using the old disk.

Does anyone have any suggestions on how to diagnose what might be going wrong?

I'm thinking either
1- The enclosure has an issue. (I bought the one recommened on the youtube video. Maybe mine is just iffy.)
2- Some issue with the SSD - MX100 256GB
3- Some issue with the fact that I left her original 1TB drive installed and didn't change anything with it. Maybe the OS gets confused about where to read/write I'm making this up because I can't explain it but maybe two boot drives something something.

Ideas? The daughter loves the speed of the SSD, but the uncertainty of reliability has killed it for now.

 

[Eug]

Here's my experience with a Firewire 800 SSD and 2010 iMac.

https://forums.anandtech.com/thread...rewire-800-ssd-as-my-imac-boot-drive.2442921/

There were lockup issues, which were due to the fact that the drive had insufficient power on bus power. All such lockup problems disappeared when I plugged in an AC adapter for the drive.

BTW, Macs don't get confused by having multiple boot disks. That is not an issue.

 

[CuriousMike]

Thanks for detailing this - unfortunately, neither of my existing USB 3 enclosures have an option for external power.
Sounds like it might be worth trolling Amazon for an inexpensive powered enclosure.

Here's my experience with a Firewire 800 SSD and 2010 iMac.

https://forums.anandtech.com/thread...rewire-800-ssd-as-my-imac-boot-drive.2442921/

There were lockup issues, which were due to the fact that the drive had insufficient power on bus power. All such lockup problems disappeared when I plugged in an AC adapter for the drive.

BTW, Macs don't get confused by having multiple boot disks. That is not an issue.

 

[Eug]

Yeah, I expected a Firewire 800 enclosure should be able to power it fine, but given my experience in the past with USB hard drives and USB optical drives using 3rd party enclosures, I made it a point to only purchase a Firewire drive that had an AC adapter option for this specific purpose, just in case. So glad I did. It's been working fine for the past year on AC power - I set this up August 2015 and it's been great. I'm typing on that iMac right now in fact.

I suspect the problem is that some computers (including Macs) just don't give 100% consistent power, which can lead to hiccups, which for a boot drive is a major issue. Even if the minimum power is on paper good enough, perhaps the fluctuations can still cause problems. This is not only an issue with hard drives and SSDs, because for example I would have major problems trying to boot off low power slim optical drives on my PCs, when I just matched such a supposedly low power slim laptop optical drive with a 3rd party USB optical enclosure. Even dual USB power wasn't good enough. With the same hardware, all such optical boot problems disappeared just by plugging the second USB cable into a real-Apple iPad AC to USB power adapter. Interestingly, using some third party fake Apple iPad AC adapter from eBay caused the same boot problems. Since then (and because I've read that the fake ones can be dangerous too), I've thrown out all of my non-OEM AC->USB power adapters. (Apple, Motorola, and Asus AC->USB power adapters seem to work fine.)

These days the only bus powered external drives I trust are those which manufactured by the actual drive makers, since they seem to spec uber-lower power usage and seem to account for the bus power issues. I've found they do much better on bus power than just picking up a random drive + 3rd party enclosure.

BTW, that reminds me, would a dual USB cable, matched up to a good quality USB power adapter work? Would that be safe for the drive on USB 3? This is what I'm talking about:

Usually people say to just plug the second USB plug into a second USB port, but as mentioned, I've discovered that's not reliable enough. Hence, I recommend using a good quality AC to USB power adapter.

 

[CuriousMike]

BTW, that reminds me, would a dual USB cable, matched up to a good quality USB power adapter work? Would that be safe for the drive on USB 3? This is what I'm talking about:

Huh - I didn't think about the dual USB cable. My external USB DVD burner has that - I'll have to check if that cable is detachable/useable with the other drive. Otherwise, I'll see if there is an inexpensive variant.

 

[Bryf50]

https://www.amazon.com/eForCity-dua...=8-1&keywords=usb+3+cable+with+external+power

Plenty of cables like this on Amazon.

 

[dave_the_nerd]

I know this was a problem with USB 2, but doesn't USB 3 provide a full 5w? (1A @ 5v)

I'm surprised your SSD draws more than that.

(There were also those "high-power" USB 2 ports that Macs had for a while, that also provided 5w instead of 2.5w, for charging iPhones and whatnot, I guess.)

 

[Eug]

I know this was a problem with USB 2, but doesn't USB 3 provide a full 5w? (1A @ 5v)

I'm surprised your SSD draws more than that.

(There were also those "high-power" USB 2 ports that Macs had for a while, that also provided 5w instead of 2.5w, for charging iPhones and whatnot, I guess.)

My Firewire port puts out even more power than that, and it's still a problem.

I suspect the power supplied might fluctuate more than a boot drive likes.