THUNDERBOLT 2 VS USB3 HARD DRIVE INTERFACE COMPARISON

THUNDERBOLT 2 HARD DRIVE ON MAC OS-X

THUNDER 2 IS A SOLID LITTLE LUNCHBOX

AKITIO THUNDER 2 QUAD HARD DRIVE ENCLOSURE WITH THUNDERBOLT INTERFACE

by Mark King

In recent years low-price and industry-standards have helped USB3 look more like a real contender for hard disk storage connections, but can USB3 deliver reliable disk drive performance with Logic Pro-X DAW software?   

Is Thunderbolt 2 any good for hard disk drives? Is it more reliable than USB3?

A real problem with the Mac Pro cylinder is the limited number of USB3 ports provided, there are only four on the CPU. On my system one feeds my Time-Machine backup drive, one is the DAW connection for my audio interface, one feeds my X-Touch DAW fader/midi interface and the last available port feeds a 1x10 USB3 dock which provides 10-more USB3 ports, that's where my iLok lives. 

HIGH SPEED SSD DRIVES ON USB3
For months I've used high-speed SSD's in Atomos video drive cases, these USB 3 interfaces have provided the fastest benchmark results of any external style case I've tested. I've also tested SSD by OWC in both the standard 2.5" format as well as their self contained SSD stick model. Since the cylinder Mac Pro has no provisions for a second internal drive some sort of external system is going to be required. For DAW applications I always recommend files be stored on an external drive while the DAW software runs on the internal drive in the CPU. This splits the read-write access demands on the two drives.

For benchmarking I like the test software provided by Black Magic design. It's easy to use and provides the most consistent representation of drive performance that I've used. The software allows you to easily select the drive you want to test, any drive attached to the system is available. After performing a test it's easy to make a screen shot of the test results for comparing. 

Over the past twenty-five years I've used SCSI, Firewire 400, Firewire 800, USB2, and USB3 technology for connecting disk drives. Before USB3 I would not have considered USB for a disk drive connection but after testing the significant performance improvements to USB3 (especially after Apple completely rewrote the driver for support in OS-X) the new USB format seemed like it had finally arrived as a drive-connection standard.

PROBLEMS
My Mac DAW is a single purpose machine, it's only job is to create and mix music. I don't use it on the internet except to connect to software upgrades. I normally leave wifi off so it can not connect in day to day operation. 

Logic X software has had teething problems and bugs persist in the software. For the most part my Mac Pro DAW runs great except when it doesn't. Periodically the system would hang-up, out of the blue and totally at random, it locks up and gives me the spinning beach ball. The only way to recover from this is a full restart of the machine. 

Another annoying problem that happens without explanation is getting random messages from Mac OS that my main storage hard disk and my Time Machine backup drive were both ejected improperly. They magically reconnect but then my Time Machine backup is no longer backing up until I restart again. This was very disconcerting and beyond annoying.

MONTHS OF TORTURE
Finally I could endure this unreliable performance no more! I had to try something different. I've already switched cables, cleaned connectors with Cramolin R5, tried premium cables, tried different drive enclosures, all were marginally unreliable in day to day use. I never lost any data from any of this drive-foolishness but I had lost time restarting and the thought of a fault waiting to sting me when I'm not looking or expecting it was too much to accept any more.

THE CURE
After trying several USB3 dock/splitter boxes and numerous replacement high-end cables I finally decided I needed to get off the USB3 bus, but where to go? I've got three unused Thunderbolt 2 ports on the Mac Pro CPU so I looked for a Thunderbolt to USB3 converter. I did not find anything that looked good, all were plagued with bad reviews.

AKITIO THUNDER 2, FOUR DRIVE ENCLOSURE

Finally I found the Akitio Thunder 2 Four-Bay hard drive enclosure. This appears to be the same basic product which OWC has sold in the past with their brand on it. The Akitio brand was quite a bit less expensive on Amazon Prime and it had a lot of reviews which were all positive. I've had some quirky performance from some of my more recent OWC purchases so I decided to give one of their competitors a try. All the positive reviews on Amazon made the choice easier. 

THE AKITIIO THUNDER 2 FOUR-BAY ENCLOSURE
This is just a bare enclosure that is made to hold up to four drive mechanisms. You don't need to install four drives, you can start with one. I started with one SSD and one Seagate 3TB 7200 RPM disk drive mechanism. 

THUNDER 2 ENCLOSURE WITH FRONT COVER REMOVED

The enclosure has two Thunderbolt 2 ports so it has an INPUT and a THRU PORT to add up to five more Thunderbolt 2 devices.

Installing drives is very easy, you slide a lock on the bottom, tip the enclosure slightly forward and the whole thing slides forward about an inch out of the box. From here you can remove drive cartridges individually by using the thumbscrews on each drive bay. The individual bays slide in and out easily, it all feels like good quality hardware. 

REMOVING DRIVE CARTRIDGE TO INSTALL DISK MECHANISM

The Thunder 2 came with a bag of screws for mounting four disk drive mechanisms in the drive cartridges. There are short screws for SSD 2.5" style drives and longer screws for full size 3.5" disk drives. The only tool required is a small phillips type screwdriver, you use this to attach a drive to the cartridge with the screws provided. 

There are no cables or wires to install, the SATA port on the drive mechanism mates to a matching connector inside the main enclosure when you slide the cartridge back into the case. I was skeptical about the fit but after trying it I'm sold, it works great, a perfect connection.

EMPTY DRIVE CARTRIDGE HOLDS 3.5" OR 2.5" SATA DRIVE MECHANISMS

THUNDER 2 DRIVE CARTRIDGE WITH SSD INSTALLED

The Thunder 2 came with a Thunderbolt cable, a nice touch because they're not cheap as accessories.

A large AC-DC power brick provides power to the Thunder 2 enclosure. There is a soft power button on the enclosure, you press this to put it into ready mode. In the ready mode the enclosure senses power on the Thunderbolt 2 bus and automatically powers up the internal fan. That fan is loud, it's my biggest complaint about this box. I'm building a sound deadening tunnel to place over the drive to quiet it way down. 

TESTING
I tested drives over USB3 and over the Thunderbolt bus after installing the drives into the Thunder 2 enclosure. There were slight differences in benchmark performance but overall both interfaces were very fast at transferring data. 

OWC ELECTRA SSD via USB3

OWC ELECTRA SSD via THUNDERBOLT 2

SAN DISK PRO SSD via USB3

SAN DISK PRO SSD via THUNDERBOLT 2

SEAGATE 3TB 7200 RPM HD via USB3

SEAGATE 3TB 7200 RPM via THUNDERBOLT 2

WD 2-TB via FIREWIRE 800

I included the final WD via Firewire 800 just as a point of reference to illustrate how far drive throughput has come. 

HISTORICAL BENCHMARK
Back in the 1990's I built a custom array of Seagate Barracuda 7200 RPM drives in a quad bay SCSI drive enclosure, that system only had 16GB of total storage and including the $200 array software it was barely able to provide a reliable 30+MB per second of capture speed for my Targa 2000 video editing system. That array and software cost almost $4500 back then but it allowed uncompressed SD video to be recorded in component quality via the Targa board in my CPU. We look at these spec's now and just laugh at how barbaric they seem by comparison to off the shelf consumer goods available today.  

RELIABILITY OF THUNDERBOLT DRIVE ENCLOSURE
This is the big one for me and the Akitio Thunder 2 has been a large improvement over my previous USB3 connections in reliability. Since switching my drives to the Thunderbolt 2 bus I've had no more system-hangs and most importantly, no weird drive disconnections. 

I currently have two SSD and one spinning 7200 RPM drive installed inside the Thunder 2, all of the drives just show up on the desktop as individual drives. I'm not using any RAID software or anything special. The drives kept their names from their previous installations in USB3 enclosures. 

CONCLUSION
I don't think USB3 is inherently unreliable, I believe that the primary source of instability I experienced is due to the dock used to split a single USB3 hole on the CPU to multiple I.O. ports on the dock, which I then fed to various drive mechanisms. It seems to me there is a need in the market for a high quality USB3 dock/splitter device that has plenty of power per port and no power saving on-off switching or monkey business, this would be the ideal host for plugging in USB3 storage drives. I tried several models and brands ranging in price from $15 to $50 for the dock alone, all of them had instability problems that showed up over time. Some budget docks share the total bandwidth across all ports so the throughput to a disk drive can actually go way down depending on what you've got connected. I uncovered this cheesy design flaw by testing with the BlackMagic software.

At around $330 the Thunder 2 quad drive enclosure is not inexpensive and it does not include disk drives. I had two SSD and a 3TB 7200 RPM drive to install inside the Thunder 2 as soon as it arrived.

I like saving my DAW work on an SSD because sessions open and close so fast. I use the second SSD to make a quick copy of whatever I'm working on for security.

For backup I keep copies on my 3TB-Seagate 7200 RPM drive and I have a 5-TB Seagate running Time-Machine backup for me as well. For archiving I also copy song sessions to the older WD 2-TB firewire drive that I've had for several years. This gives me at least three copies of the material plus the Time-Machine backup.

Firewire 800 served me well for many years but the data throughput performance of my remaining Firewire 800 drive(s) compared to everything else looks painfully slow on the benchmark tests. I've mixed songs with 40-tracks over Firewire 800, it was a great external bus for many years.

I'll update this article in the future as more data comes in from using the Thunder-2 from Akitio, for now, I'm impressed. So far it seems to have settled a big problem for me, I hope the problem stays solved!

Good luck and good music to all!