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OWC ThunderBay 4 mini

Enclosure Portable 4-Bay External Drive

Dual Thunderbolt 2 | RAID Ready | 4 Drive Bays | Mac
The Speed You Need
  • Four 2.5" drive bays, perfect for SSDs
  • Breathtaking Thunderbolt 2 performance
  • RAID-ready
  • Up to 1346MB/s read / 1321MB/s write RAID 0 performance*
Empower your production workflow on-the-go with this super-fast, 4-Bay, RAID-ready enclosure kit. Optimized for 2.5" drives and perfect for SSDs, ThunderBay 4 mini takes your creativity to the next level by supporting the most demanding applications, including workflows involving 4K, 2K, uncompressed HD, and multi-stream SD video. Easily transport your data between production environments with this portable, professional-grade Thunderbolt 2 powerhouse.
Do more with a ThunderBay enhanced workflow.
Expand production capabilities in industry-leading creative platforms like Final Cut X, Avid Pro Tools, and Adobe Lightroom with this incredibly fast and portable 4-bay drive.

With the ThunderBay 4 mini enclosure kit, you can add up to four 2.5" hard drives, SSDs, or a mix of both to suit your performance needs. Utilize the drives independently, or use the software RAID configuration of your choice to achieve an optimal balance of storage, performance, and data-redundancy.
4 drive bays plus so much more.
Time-tested Cooling Cool + Whisper Quiet
A durable, heat-dissipating, aluminum unibody shell features a "flow-thru" vented design coupled with a 60 mm whisper-quiet fan.
DisplayPort 1.2 4K Display Support
Dual Thunderbolt 2 ports let you connect any display that your computer can support, including 4K displays.
Vibration Dampened Vibration Dampened
ThunderBay's drive isolating design reduces sonic resonance, and is aided by rugged, vibration-absorbing, non-skid feet.
Multi-Drive Flexible Expansion
Daisy-chain up to six ThunderBays on a single Thunderbolt port for expansive storage, RAID, and performance options.
Thunderbolt Cable OWC Thunderbolt Cable
ThunderBay comes with an OWC one-meter certified Thunderbolt cable, with other lengths from 0.5 meter to 30 meters available separately.

*Speed dependent on drive mechanism


  • OWC ThunderBay 4 mini High-performance 4-bay Thunderbolt 2 interface drive
  • High-Quality, Certified, Double-Shielded 1-Meter Thunderbolt cable
  • External UL listed 3-prong power cable
  • 2 keys for front panel lock
  • Quick Start Guide
  • OWC ThunderBay 4 mini Assembly Manual & User Guide (Download Only)
  • Utility software bundle for Mac and PC
  • 1 Year OWC Enclosure Limited Warranty


Product Specifications

Mechanisms Supported

  • Four 2.5" SATA 6Gb/s drives (up to 15mm height)


  • Thunderbolt 2

Interfaces Supported

  • Thunderbolt 2

JBOD / RAID Support

  • JBOD: Utilize each of the four drives independently
  • RAID: Use any Software RAID of your choice to setup the ThunderBay 4 for multi-drive performance or data redundancy.

Port Configuration

  • Thunderbolt – (2) Thunderbolt 2 ports

Max Data Transfer Rate

  • Thunderbolt 2 – 20Gb/sec

Port/Interface Bootability

  • It can be used as a Thunderbolt startup drive on Macs running Mac OS X.

System Requirements

  • Any Mac with a Thunderbolt port running OS X 10.9 or later.
  • Any PC running Windows 7 Service Pack 1 or later with a Thunderbolt port. Driver required for proper installation. (3.3 MB ZIP)
  • Boot Camp is not supported. The Thunderbolt certification process does not include Macs running Windows through Boot Camp.

Power Supply

  • UL Listed U.S./International Auto Switching 100 ~ 240v, 50/60Hz input, 12 Volt 6.0 Amp output Power Supply (power cords for International use sold separately).

Software Included

External Case Dimensions

  • 7.6"(D) x 3.8"(W) x 4.6"(H)
  • 19.3cm x 9.6cm x 11.6cm

Enclosure Weight (no accessories)

  • Approximately 2.4 pounds (1.1kg)

Operating Environment:


  • (operating) 5°C – 42°C (41°F – 107°F)
  • (non-operating) -40°C – 65°C (-40°F – 149°F)

Relative Humidity

  • (operating) 8% – 90% RH (Non-condensing)
  • (non-operating) 5% – 95% RH (Non-condensing)


  • 65G 2mS; (non-operating) 175G 2mS


  • (operating) 1.0G (5 – 300Hz)
  • (non-operating) 5.0G (5 – 500Hz)


1 Year OWC Enclosure Limited Warranty

The best warranty is one you never have to use, but should the need occur – OWC is proud to provide a superior level of support and warranty coverage to our customers. Even when not used, we understand the peace of mind afforded by a longer warranty period. OWC's industry leading coverage is a testament to our confidence in the reliability of the solutions that we offer. OWC solutions are engineered to demanding quality standards in order to deliver the most reliable, highest performance available on the market in each storage category.

View more information about the 1 Year OWC Enclosure Limited Warranty

Manufacturer provided specifications for Other World Computing p/n TB4MJB0GB UPC#: 812437020922


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Intech SpeedTools Utilities
Intech® SpeedTools Utilities™
Intech SpeedTools consists of a suite of utilities managed by an application which controls the launching, documentation and version control of each individual component utility, such as Disk Defrag and QuickBack. An easy-to-use installation and removal application is provided to make installation a snap, yet powerful enough to allow you to customize which utility component set you would like to create.
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Customer Ratings

Write a Review 4.7 / 5 12 out of 14 (86%) reviewers would recommend this product
Verified Buyer
Reviewer: ColoradoBound Location: Colorado Age: 45-54 Experience Level: Power User Owned Product: over 6 months
Rating: 4/5 Good Unit November 7, 2016 I have been happy with my drive enclosure. It is small and nice and quiet. The only negative I have is that it uses too much power. I was building a low power server based on a Mac Mini and this enclosure and even without any SSD drives installed it uses more power than the Mac Mini.

I would recommend this item to a friend! Customer Videos:

Verified Buyer
Reviewer: EnforcerViper Location: Winnipeg Age: 35-44 Experience Level: IT Professional Owned Product: over 6 months
Rating: 5/5 Very reliable! August 30, 2016 I have two of these, both filled with SSD drives and they have both been flawless and rock solid. The thunderbolt connection is wicked fast.

I would recommend this item to a friend! Customer Videos:

Reviewer: Anurag Location: New York Age: 35-44 Experience Level: Power User Owned Product: over 6 months
Rating: 3/5 Good but quite noisy August 29, 2016 The whole idea of getting an SSD storage array was to get something I can keep on my desk. However, with the Thunderbay 4 mini I cannot do that. The drives are quite but the fan is way too noisy. They rally need a spend a couple more bucks on a quality fan to make this a quality product. What compounds this is that the drives don't sleep when not used but only when the entire computer goes to sleep - which for me only happens at night.

I read others having replaced the fan with a much quieter noctua fan - but unfortunately I could not figure out how to do that.

Highly recommend OWC make a truly quiet device the next time.

Customer Videos:

Response from MacSales.com, Product Development August 30, 2016 In May we moved to a brand new fan solution and reduced/eliminated the noise level from the fan noted. We are always listening to all customer feedback and further working to improve products on an ongoing basis and fan noise was high on the list from the beginning and something that was successfully mitigated with product currently shipping.
Reviewer: Anonymous Location: Central Texas Age: 25-34 Experience Level: Power User Owned Product: 1-3 months
Rating: 5/5 Excellent! June 12, 2016 This awesome little device works exactly as it is supposed to! I took several old hard drives from previous laptops, reformatted them, and put them into this enclosure. They worked immediately! Two of them or solid-state drive, and they read and write almost as fast as if the hard drives when the laptop itself. I recommend this product to anyone! You definitely get what you pay for!

I would recommend this item to a friend!

Reviewer: Anonymous Location: Vallejo, CA Age: 55-65 Experience Level: IT Professional Owned Product: less than a month
Rating: 5/5 Goodbye internal drive bays, Hello Thunderbay Mini! February 29, 2016 I put off moving to a new computer for a long time because I didn't want to lose the 4 drive bays on my trusty Mac Pro 1.1. Finally bit the bullet, if getting a gorgeous 27inch iMac can be called "biting the bullet". Thunderbay Mini to the rescue for my data storage.

I've been putting it, (and SoftRaid) through their paces and so far the performance is admirable. I love the small form factor. I am using 2 units with OBR10 (one big RAID 10) across 8 2TB drives, giving 8TB of highly redundant data storage. A 3rd set of disks will serve as offsite storage, to be swapped with one set of mirrors on a periodic basis. Should keep me for awhile, at least until the next bump in drive sizes.

Only 2 nits to pick. One is the markings for the drive lights are practically invisible. Not that big a deal for such a compact device; you can identify the lights positionally. But still, someone did go to the trouble of specifying and implementing markings. I'm at a loss as to why making them actually be visible did not seem to be a concern.

Second nit is with the associated Soft Raid product. The software has been working quite well, and does its job very efficiently. However there does seem to be a lot of promotion of RAID 5 as a storage strategy. In part due to that, my initial direction was with RAID 5. Upon further research I have run across many warnings that RAID 5 is definitely not recommended for modern drive sizes, and considered a bad option. Research RAID 5 and "URE" (unrecoverable read error). Once you get past a certain disk size it is quite likely that the storage array will ruin itself when attempting to recover after loss of any disk. RAID 10 is considered far safer for your data.

In short, a very valuable product for me, 5 stars but make sure to do your research and carefully consider your RAID storage options before finalizing your decision.

I would recommend this item to a friend!

Verified Buyer
Reviewer: Anonymous Location: Bowling Green, OH
Rating: 5/5 Very quiet and unobtrusive January 16, 2016 My new OWC ThunderBay 4 mini has been working perfectly. I've filled it with 4 400GB SSDs. It is absolutely quiet.

Verified Buyer
Reviewer: Anonymous
Rating: 5/5 Does what it says on the tin August 3, 2015 The most efficient way for me to carry 4 2.5" drives. Thank you OWC

I would recommend this item to a friend!

Verified Buyer Top 100 Contributor
Reviewer: Anonymous Location: Rockville, MD Experience Level: IT Professional Owned Product: 1-3 months
Rating: 5/5 Superior to other enclosures I've tried July 31, 2015 Replaced a Promise RAID enclosure that never worked properly. This one is high quality construction. Has been problem free since I installed my 4 SSDs as RAID 10. And of course with thunderbolt 2 it is extra fast. Nice product. Highly recommended.

I would recommend this item to a friend!

Verified Buyer
Reviewer: Anonymous Location: Los Angeles, CA Age: 45-54 Experience Level: IT Professional Owned Product: 1-3 months
Rating: 5/5 Works great April 28, 2015 Easy to assemble, ordered SSD drives and popped them in, works flawlessly and is silent.

I would recommend this item to a friend!

Verified Buyer
Reviewer: Anonymous Location: Cincinnati Age: 45-54 Experience Level: IT Professional Owned Product: 1-3 months
Rating: 5/5 Does what they say March 15, 2015 It's not a complex product. You stick in SSD drives and it works. I was interested because it had a Thunderbolt 2 connection. I've had it for a month or so and had no issues with it. I would recommend it to anyone looking for an external RAID array on a Mac.

I would recommend this item to a friend!

Verified Buyer
Reviewer: Anonymous Location: SLC,UT Age: 55-65 Experience Level: Hobbiest Owned Product: 1-3 months
Rating: 5/5 Great Product March 11, 2015 This case is well made. I have four SSD,s in raid 0 with OS X installed and no problems. Black Magic test Read 1184 MB/s Write 1085 MB/s

I would recommend this item to a friend!

Verified Buyer
Reviewer: Anonymous Location: Napa Age: 45-54 Experience Level: Power User Owned Product: 1-3 months
Rating: 4/5 The enclosure is awesome January 12, 2015 but hard drives stink. I've been wanting an enclosure like this for years, so I jumped on it as soon as it was announced. I wanted a fast, quiet, RAID hard drive, and this is all three. I was expecting faster performance than I got, but that's the fault of the four 2TB drives inside. I'm getting about 500MB/s in RAID 0. Once the cost of SSDs decline, then I'll make the switch.

I would recommend this item to a friend!

Verified Buyer
Reviewer: Anonymous Location: Tampa, FL Age: 45-54 Experience Level: Power User Owned Product: 3-4 months
Rating: 5/5 Thunder bay Mini 4 - Outstanding Product January 3, 2015 Moved from a 2010 Mac Pro to a 2014 MacBook Pro. I delayed the moved because my Mac Pro was maxed out with 4 Disk Drives and I wasn't sure what to do migrating to the MBPro. I knew I could count on OWC and just about the time I was ready to move on the "Thunder Bay 4" the "Thunder Bay 4 mini" was introduced. I called tech support with questions on the mini and it seemed like what I was waiting for. I migrated two existing SSD's (One OWC) for the Mac Pro and bought two more SSD's from OWC to fill up the Thunder Bay mini 4. Mission accomplished!! As a bonus I have the option to boot from the Thunder Bay Mini vis a vie Thunderbolt2 should I choose(Contrary to what Mac Support said and it works, I tried it). The Thunder Bay Mini 4 is Fast, Quiet and Runs Cool.

I would recommend this item to a friend!

Verified Buyer
Reviewer: Anonymous Location: Gold Coast, Australia Age: 45-54 Experience Level: Power User Owned Product: 1-3 months
Rating: 5/5 Excellent drive enclosure December 21, 2014 I have been using the Thunderbay 4 mini for just under a month now and it works exactly as advertised.

One of the best features is the cooling fan which maintains my SSDs at a comfortable 29° C vs 45° C in Akitio Neutrino Thunder Duo which I previously used.

I would recommend this item to a friend!

OWC Enclosure ThunderBay 4 mini Mfr P/N: TB4MJB0GB MacSales.com SKU: OWCTB4MJB0GB High-Performance 4-bay External Drive 1 Year OWC Limited Warranty Ships: Same Day Only $394.99MacSales.com Price $347.99
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