Hey there, I recently purchased an Oyen Digital Mobius 5-bay RAID diskless enclosure and thought I would share my decision making process and findings with everyone. What's it for The purpose of the purchase was to provide a large DAS solution for my Plex HTPC 2010 Mac Mini (soon to be a 2012 i7 Mini) which also serves as a NAS for the rest of my household. My previous solution was a couple of large drives in a Sans Digital 2-bay enclosure connected in JBOD for storing videos and backups of my photos. With that solution nearly bursting at the seams I wanted something with more capacity. My Requirements - 10TB or more of storage in a single volume for growth/ease of management - Easy to recover from a drive failure (much more on that below) - Speed wasn't a requirement - Neither Plex nor GigE NAS requires much speed - Hence FW800 and USB3 we're fine for interfaces (and I wanted both) - Fairly quiet (will be part of my home theater setup). - Black (to match the rest of my home theater setup). Why the Mobius I really needed more than 8TB for future growth and that discounted any 2-bay enclosures. So I looked at my choices with 4 and 5 bay enclosures. I discounted Thunderbolt because I didn't need that level of performance and so wouldn't get any value out of paying a premium for it. The Mobius had the best reviews of any enclosure out there, was very reasonably priced, and met all my requirements, so it seemed like an easy choice. RAID or not to RAID In my case, the data I'm storing is not super critical. Since it's a media collection and backups of my photos, its all stuff that exists elsewhere. However, I still didn't want to have to re-download or re-rip a bunch of movies if a drive failed so some kind of backup or RAID was definitely a requirement. I've never been a proponent of parity RAID (e.g. RAID5 or RAID6). In fact, if you read up on RAID5, you'll find it was declared dead a few years ago with the introduction of 3TB drives which according to the stats, pretty much ensure a non-recoverable read error during a rebuild in the event of a drive failure and a total loss of the array. Even if the rebuild is successful, it's going to take days with a large array and that in and of itself creates added risk of a total loss. And of course, you're running that whole time in a degraded state. Apparently, it's got to the point now where some IT professionals are saying it's better to suffer the down time necessary to restore from a backup than try to operate while a parity RAID array is rebuilding. Anyway, I discounted parity RAID. That left me with two choices... RAID10 or RAID0 with a backup. (I also considered ZFS but solutions seem to come and go with the wind - without native OS X support, it's not a viable long-term solution IMHO). The benefits of RAID10 are it's redundancy, performance, and simplicity. The downside is the cost... for 10TB of storage, I would need 4x 5TB drives. At any rate, this is what I initially decided to do and thus ordered four 5TB Seagate drives. More on drive choice below. However, I started thinking that maybe I didn't need that level of redundancy. Downtime in the event of a drive failure wasn't a huge issue... it's not like a business was dependent on this storage. However, I definitely wanted a backup in the event of a drive failure, and so started thinking about what that would entail. It turns out, I keep an offsite backup of my photos on externals already (as well as a copy on an external on my Mac Pro) so mirroring that again at home didn't make sense. I also concluded that since my old JBOD drives already had digital copies of all the video content I could just shelve those as offline backups. The only thing left to backup then, was any NEW video content I accumulated. So I decided I'd just do that with a single external drive. Any new content would be backed up to the stand-alone external on a weekly basis. When that drive filled up, I'd shelve it, and buy another. So in the end, I opted to run the 4x 5TB drives in a RAID0 array in the Mobius for a huge 20TB volume... with a 3TB external for backups that would be replaced with a new one whenever it got full. Drive Choice Since I wasn't using parity RAID, I didn't need to limit myself (and pay extra for) NAS or RAID hard drives like RED, RE4, Constellation, etc. I've never been brand loyal in storage, so I was open to anything. In my research, I came across this great Backblaze article. What I concluded was that all drive brands can burn out and fail and buying the cheapest desktop consumer drives for non performance critical mass storage was the way to go and if I have to replace one in a couple of years, so be it... the difference between four cheap drives and four RAID or enterprise drives can be as much as replacing each drive (and replacing a 5TB drive in two years will cost half as much as it does today). It turns out the cheapest on a per GB basis I could find currently were Seagate ST5000DM000 drives from the same family as Backblaze recommended. The cheapest (only) way to get these currently is to buy them in Seagates Backup Expansion externals. Of course you only get a 1 year warranty (well technically no warranty if you remove them from the enclosure), but the cost of replacing the drive down the road in 2 or 3 years is not as much an issue for me as saving some decent money up front now. Others priorities may be different. The 5TB externals were only $10 more than 4TB bare drives and almost half the price of 5TB REDs. Financially they were the sensible choice. Mobius The OyenDigital Mobius is a nice chassis. It's made out of black aluminum and is about the height of 5 drives stacked together with a depth equivalent to about 150% of a 3.5" drive. I really like the tool-less drive bays... just slide the drive in and then close the bay door to seat the drive and secure it in the bay. This is in contrast to the SansDigital enclosure I use to have where you had to attach the drive rails and door to the drive with 6 screws before inserting the whole thing into the open bay. The documentation with the product is simple and adequate. They also include all the cables you would need (FW, USB, eSATA, and AC power). Performance I tested the enclosure connected to my 2013 nMP via USB3. I tried the enclosure using JBOD mode and setting up a 4x RAID0 array in Disk Utility, and then I also tried setting it up in a RAID0 array using the Mobius Hardware RAID function. The results are thus (all tests done with QuickBench on the 2013 Mac Pro via USB3): Before using the Mobius: Test 1: Single Seagate ST5000DM000 in External USB3 Enclosure Max Sequential Read: 189MB/s Max Sequential Write: 190MB/s Random Read 4K: 0.757MB/s Random Write 4K: 5.019MB/s Note: Impressive performance for a single drive. Test 2: 4x Seagate ST5000DM000 in External USB3 Enclosures - Disk Utility RAID0 Max Sequential Read: 349MB/s Max Sequential Write: 387MB/s Random Read 4K: 0.990MB/s Random Write 4K: 5.967MB/s Note: In this test each external was connected to a separate USB3 port on the nMP and the RAID0 array was setup in Disk Utility. It seems the nMP's upper limit on USB3 throughput is 350MB/s ideally it should have been closer to 500MB/s. After installing the drives in the Mobius: Test 3: 4x Seagate ST5000DM000 in Mobius - Disk Utility Software RAID0 Max Sequential Read: 213MB/s Max Sequential Write: 236MB/s Random Read 4K: 0.932MB/s Random Write 4K: 6.667MB/s Note: Clearly less throughput with the Mobius aggregating all the drives through a single USB3 connection compared to all drives connected via their own USB3 port. Test 4: 4x Seagate ST5000DM000 in Mobius - Mobius Hardware RAID0 Max Sequential Read: 253MB/s Max Sequential Write: 242MB/s Random Read 4K: 0.695MB/s Random Write 4K: 0.529MB/s Note: Somewhat better sequential read performance but dramatically worse performance with small files... an order of magnitude worse performance on 4K random writes. I repeated the small file tests multiple times and even in real-world file copy tests, the Mobius was just unusable with these drives in HW RAID0. I contacted Oyen Digital support and they verified the results with a set of three 4TB WD REDs in their lab and confirmed that the JMicron chip that handles RAID in the Mobius is just not suited for HW RAID0 where small files might be involved. In a real world test of copying a 75GB Aperture Library from my nMP SSD to the Mobius, it took 10:23min in HW RAID0 (average of 120MB/s) and only 6:45min in SW RAID0 (~185MB/s). In fact, in any real world file copy tests I did, SW RAID0 (via Disk Utility) beat the Mobius built-in HW RAID0 every time. I didn't try any other RAID modes so I don't know how it's performance is in RAID5 or RAID6... but if you're going to use it for RAID0 or RAID10, you're probably better off using Disk Utility anyway. Sleep/Wake Another issue I had was with Sleep. The enclosure would put itself to sleep after 20minutes no matter what. I disabled the option to "sleep drives when possible" in System Preferences but that didn't help. I contacted Oyen Digital support and was advised to load a previous firmware build (dated 2-19) that would not sleep. I did this and it's working 24/7 to my satisfaction now. It appears to cycle the drives in some way every minute to prevent drives from going to sleep on their own (apparently a function of some HDs). The good news is that their JMicron firmware update tool and RAID monitoring tool is available for the Mac. When waking from Sleep, it does so in a reasonable time, but it's not as quick as my Velociraptor Duo. It takes maybe 10 seconds which can feel like an eternity waiting for something to load on your computer. And it can be disconcerting because while it's sleeping the volume is still mounted and you can click to open it in Finder but you won't see any folders or files until it's fully awake so the first time you see this you might be somewhat alarmed. Portability I was pleasantly surprised to find that I could move the enclosure between my Mac Mini with Firewire (running 10.10 beta) and my nMP with USB3 (running 10.9.4) without any issues... the enclosure worked equally as well and the array was fully visible and accessible on both systems. Similarly sharing the volume across my home network works as it would with any shared drive. There is no handle so you have to put it under your arm, and it is reasonably heavy with four drives loaded up. Sound When it was sitting next to my Mac Pro it was definitely audible... but more so because of the four spinning disks inside than from it's own cooling fan. However when I installed it in my entertainment centre, I could not hear it from 10' away where I normally sit. It is less noisy than the SansDigital enclosure I had which had a tiny little fan compared to the larger pair of fans on the Mobius. A nice-to-have option would be to turn one of it's two fans off... I honestly don't think it really needs dual fan cooling in my environment. Conclusion The Mobius is not completely flawless, but it is the best solution I'm aware of that meets my requirements. - It's very reasonably priced (at $229 USD) - It offers plenty of storage options with 5-bays - It's nicely designed and integrates will with either the nMP or my HTPC setup. - It's not obnoxiously loud. - It's been operating 24/7 without a hiccup now for a couple of weeks. - Oyen Digital support was responsive and knowledgeable (and based in the US) - It's performance is certainly adequate for HTPC, Backup, or NAS type duties (using Disk Utility to setup the RAID0 array) Would I recommend it to others? Yes... if you need a flexible large volume storage solution for your media, backups, or NAS duties. But I would probably not recommend this for storage that was involved in your project workflow. It's performance in RAID0 is not much better than a single drive. Instead, I'd definitely recommend folks get as much SSD storage as possible for project work (I have 1TB on my nMP for my current Aperture library), and then when you've exhausted that look at Thunderbolt drive enclosures like the Oyen Digital DataTale, Promise Pegasus or the WD Velociraptor Duo (which I have and am very pleased with for archiving Aperture Libraries). And if you don't want to pay for Thunderbolt, even a couple of large USB3 externals each directly connected via USB3 will offer better performance in SW RAID0 than this enclosure. If you have any questions, I'll do my best to answer.