mah0

macrumors newbie
Original poster
Nov 29, 2017
6
1
Hey Guys,

I recently joined the Mac community (and MacRumours too) by buying a brand new 5K iMac from 2017.

Since I have some spare SSDs from my old windows computer laying around here, I wondered how to use them with my new iMac.

After some brain storming, I came to the conclusion that I would like to use them in an external raid-array. In order to do so, I would like to use an external case with USB 3.0 or 3.1 support, as Thunderbolt 3 is rather expensive and probably an overkill in terms of speed.

However, a main requirement is that the external case has an auto ON-OFF function, so that I dont have to turn on/off the case each time I use or not use my machine.

Do you have any suggestions, which cases fit my requirements?

Best
Max
 

ZapNZs

macrumors 68020
Jan 23, 2017
2,310
1,158
Which RAID level are you thinking about using them for? Are the SSDs the same size/brand? Have you verified via SMART that they are in good health?

Your iMac supports USB 3.1 gen 2 (over USB-C), with solid SSDs and the right gen 2 enclosure, in a RAID 0 stripe, you could get upwards of 800 MB/s sustained transfer speeds (at the expense of a higher probability of data loss because, should one SSD fail, then the data on the other is useless - necessitating more vigilant backups.)

Mediasonic makes one product that serves this function, which some Users on this forum have spoken highly of. This unit can also function in JBOD, and RAID 1 (mirrored). Oyen Digital makes a similar product - I have personally used their eSATA version of their 2.5-inch RAID 0/1 enclosure and am happy with its build quality and performance - I can't speak to the USB 3.1 gen 2 version as it has a totally different chipset, but I like the company quite a lot.
 

LorenK

macrumors 6502
Dec 26, 2007
387
152
Illinois
I don't know about the auto-on-off function, but I have my back-up RAID array over several Icydocks, which you can find at a variety of websites. I like them because they hold four drives in the enclosure and are more open than other enclosures I've used. I have burned out the chipsets in a number of enclosures through heavy use and I'm hoping that the Icydocks don't suffer the same fate.
 

mah0

macrumors newbie
Original poster
Nov 29, 2017
6
1
Thanks a lot for your answers.

Which RAID level are you thinking about using them for?

I'll probably just leave them as they are (as separate disks), alternatively I’ll go with a Raid 0. Since I’m not going to use them for viable/important data, I'll probably go with the latter one.

Are the SSDs the same size/brand? Have you verified via SMART that they are in good health?

I've got two Samsung 850 evos with 256GB that are only a couple of months old. SMART status is fine.


In terms of the external HDD case, it came to my mind that I also could use a simple Master/Slave outlet. Put the iMac in the Master outlet and the external SSDs into the Slave, which would supposedly the best price-performance ratio.
 

ZapNZs

macrumors 68020
Jan 23, 2017
2,310
1,158
Thanks a lot for your answers.



I'll probably just leave them as they are (as separate disks), alternatively I’ll go with a Raid 0. Since I’m not going to use them for viable/important data, I'll probably go with the latter one.



I've got two Samsung 850 evos with 256GB that are only a couple of months old. SMART status is fine.


In terms of the external HDD case, it came to my mind that I also could use a simple Master/Slave outlet. Put the iMac in the Master outlet and the external SSDs into the Slave, which would supposedly the best price-performance ratio.

RAID0 those suckers! (if for no other reason than just for the pure novelty)

I can't speak to the RAID0 enclosures (and a RAID5 HDD enclosure I am using behaves differently, so it may be different?), but the various single-disk enclosures I am using with my Thunderbolt hub go into a deep sleep mode when the system is powered off (I am not sure if this slumber mode is being activated by the computer, or the computer activates the hub which then is what sets the drives into slumber mode?) On some of the enclosures the LEDs will go out completely, where as with others they dim and some they do not change at all - but playing around with my UPS which shows power draw (probably not super accurate?), presumably all of them (including the SSDs) are in some sort of a deep sleep or slumber mode because they don't even register 1W total consumption on the UPS at this point. All automatically turn back on when the system is powered back up. (Sorry if that isn't very helpful - someone smarter than me might have a better technical explanation, as this is more of my observations!)
 
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