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moredrunkmale

macrumors member
Original poster
Aug 22, 2010
68
0
Hey guys,

I have a dual bay external hard drive enclosure, containing 2 x 2TB drives in jbod. I was wondering if i purchased a new enclosure (also dual bay, but from a different manufacturer), in order to get USB 3.0 port, if i can just plug in my hard drives, and set new enclosure to jbod and continue using as i was.

I fear buying new enclosure and realising i have to wipe both my drives when installing them.
 
Make sure it's definitely set to JBOD or better yet, only capable of JBOD in the first place before fitting the drives and you should have no problems.

If it offers other RAID levels, it may format the drives after you fit them if it isn't set to JBOD and then you will lose your data. There's an option called BIG in some RAID configurations that will join both drives together as one volume and shouldn't be confused with JBOD.
 
JBoD and connection speed

Greetings. I signed in to post on another forum about JBoD and saw yours, so I'll post (effectively the same) message here...

If you are moving from USB2 to USB3 just for speed and you are NOT using SSDs you will notice no difference and will have wasted your money. If you are changing housing because the old one is dead or dying. No problems. As long as the number of disks remains the same.

If you want a faster external system, switch to RAID. RAID 5 is the best compromise - faster than mirroring, safer than striping, lets you have more storage space than either. RAID 10 (or 01 if you prefer - at 4 drives it doesn't matter) is faster and safer than RAID 5, but you lose storage. e.g. 4x1TB RAID 10 = 2TB available. 4x1TB RAID 5 = 2.7TB available. Choose your poison. Of course, switching from a 2 disk JBoD system to a 4 disk RAID system is much more expensive. But when you've copied over your files, you can sell your JBoD system including HDD.

But I would not waste my money moving a 2 disk JBoD from USB2 to USB3.
 
If you are moving from USB2 to USB3 just for speed and you are NOT using SSDs you will notice no difference and will have wasted your money. If you are changing housing because the old one is dead or dying. No problems. As long as the number of disks remains the same.

But I would not waste my money moving a 2 disk JBoD from USB2 to USB3.

this simply is not true. even with spinning discs you will notice a speed increase from USB2 to USB3

i have and use externals on both USB2 and USB3 - it's noticeably faster

(i also run 2x2 lacie 2bigs in RAID0 - now THAT'S fast)
 
this simply is not true. even with spinning discs you will notice a speed increase from USB2 to USB3

i have and use externals on both USB2 and USB3 - it's noticeably faster

(i also run 2x2 lacie 2bigs in RAID0 - now THAT'S fast)

I concur. This isn't SATA 2 to SATA 3. USB 2.0 has a streaming rate of 20MB/s-30MB/s. That 480 Mb/s (60 MB/s) is a burst rate. Even the burst rate is something a lot of hard drives these days can easily surpass.
 
Mea culpa

Yes, correct. I exaggerated (I was coming from a Thunderbolt forum post - apologies. I got my brain lost in that issue and was mixing things up.) Regardless, having used USB2, Firewire 800, eSATA and Thunderbolt external drives it makes more sense to switch to RAID if you can afford it. Since most fast 7200 rpm HDD max at around 156MB/s, much faster than USB2s peak rate of 480Mb/s (60MB/s), you will notice an upgrade. If you have fast drives. And JBoD, especially if you set it up as a single disk, is slower than the individual drives (due to to overhead of organizing multiple drives.) Even if you have slow drives, moving to RAID 5 will blow that out of the water. I'm getting near 500MB/s over Thunderbolt. Yes, that's faster than USB3, but since the peak rate of USB3 is 5Gb/s (>600MB/s), you should be able to achieve similar speeds with USB3 - depends on the RAID controller.
 
Yes, correct. I exaggerated (I was coming from a Thunderbolt forum post - apologies. I got my brain lost in that issue and was mixing things up.) Regardless, having used USB2, Firewire 800, eSATA and Thunderbolt external drives it makes more sense to switch to RAID if you can afford it. Since most fast 7200 rpm HDD max at around 156MB/s, much faster than USB2s peak rate of 480Mb/s (60MB/s), you will notice an upgrade. If you have fast drives. And JBoD, especially if you set it up as a single disk, is slower than the individual drives (due to to overhead of organizing multiple drives.) Even if you have slow drives, moving to RAID 5 will blow that out of the water. I'm getting near 500MB/s over Thunderbolt. Yes, that's faster than USB3, but since the peak rate of USB3 is 5Gb/s (>600MB/s), you should be able to achieve similar speeds with USB3 - depends on the RAID controller.

But the OP didn't ask for advice on RAID setups - he just wanted to know if he can use his exisiting drives in a new enclosure without losing data from them. To use the drives in RAID he'd have to move all the data onto another drive(s) first.

RAID is great for sure - but not everyone needs or wants it!
 
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