External bus-powered disks

Posted on 16 June 2013


I am looking for 4 TB external storage space (note that for 32 bit systems, 2.2 TB is the maximum size of one partition). As I want to be able to use it on the road I’d like it to be bus-powered. It would also be nice if it’s daisy-chainable and hardware encrypted.

In this post I use (D,P) which means: Daisy Chainable, Bus-Powered. I also mention things like 65/55 MB/s which means: 65 MB/s write, 65 MB/s read speeds, measured with AJA system test 1920×1080@8bit, 1 GB.

Because I want to be able to copy the whole disk in half a day (in case of a drive failure) i’d like it to be 300 MB/s avarage for video files: it’s the 3G speed of full HD 50p video and at that speed it only takes an hour to transfer 1 TB (which is important of your main drive fails and you need to copy from your backup drive). But 150 MB/s is more realistic for HDD’s (see my speed tests here).


The first choice is the connector, see my seperate post. My MBP only comes with USB 2 and FW 800. USB 2 is too slow (at 30 MB/s it takes 10 hours to transfer 1TB) . FW800 is great for bus-power and daisy chaining but limited to about 80 MB/s max speed (will still take about 3’30 hours for 1 TB).

The future is either USB3, eSATAp or Thunderbolt. Thunderbolt is not possible with my current MBP (there are no expresscards that add thunderbolt to the laptop). For USB3 and eSATAp I will need a € 40 expresscard.  There are two disadvantages of using an expresscard solution: I can’t use it together with my fast SD-cardreader so instant backups of my footage will be a pain, and it might not be compatible with a later to buy MBP docking station or new MBP. And there might be a 5V bus-power problem, see my seperate post on connectors for more.

  • USB3 is widespread, supports bus-power and is capable of reaching 300 MB/s ( the expresscard slot is limited to 300 MB/s too).This might be the best solution as the new WD external drives even come with usb3 controllers onboard instead of SATA. But there are a few disadvantages: it will be slower then an eSATA due to the Expresscard -> USB3 -> SATA bridge, and USB is more processor intensive then SATA.
  • eSATAp. Supports SMART and sleep modes of the drives.

The best bet would be to have FW800 for now and SATA to connect it a Thunderbold dock in the future. In the meantime for speed and other laptops a SATA to eSATAp or USB3 connection would be nice.

3.5″ Disks

How much faster are 3,5″ disks, is it worth the extra space and hassle of power adapters? Look at the EUR 350 4GB Lacie Quadra: FW800 for now, eSATA and USB 3 for the future. Or the 2bay version. But I don’t want Lacie, and I don’t want a fan in the housing. So I could buy the WD MyBook Studio II (up to 6TB in Raid1): FW800 (chainable?), eSATA, FW400 and USB. Or buy this $ 70 USB3/eSATA enclosure (up to 2x 4GB in SM, RAID 0 or RAID 1, with SMART) plus 2x € 70 2TB disks. But I don’t like the risk of gravity as these 3.5″ drives do not have a hardware shockguard.

2.5″ Disks

So back to the bus-powered 2,5″ disks:

  • The € 100 Oyen Digital 1 TB U32 Shadow is the smallest aluminum  1 TB drive at the moment (124x73x12 mm). This one supports UASP.
  • The € 120 WD 2 TB My Passport drive with hardware encryption and USB3 (P, 3.8W) is 110x82x21 mm. They also have a € 75 1 TB version (19mm) or the € 90 1 TB ultra (110x82x15mm) drives. One thing you need to know is that with these drives, the USB controller and USB port are integrated in the drive, so it cannot be removed and built into another case. I am using a few WD drives already and am very happy with them. I found that they always have the FDE (hardware encryption) on, with a predefined key I guess. because when you change or disable the password it does not need to change anything on the drive. The password really is only to unlock the key. So I am interested if the speed holds up to the Lacie and Gtech drives. This speed test comes with 104/106 MB/s (sequential) and 68/102 MB/s (16 GB video, with AS SSD). WD Elements Portable goes up to 2 TB but does not have hardware encryption like the My Passport drives do, they might even be faster?
  • The € 160 WD MyPassport Studio 2TB FW800 (D,P) + USB2, which can be FW daisy chained up to five at least, all bus powered by the MBP. It also has hardware encryption and there is a rugged case available too (size: 126x84x24 mm). But unfortunately, no USB3. This guy took them apart and it got a WD Green SATA disk inside, he put it in his MBP (it was to thick to fit) and got 105MB/s speeds. This guy tested it with FW800 and the +TURBO drivers and got 65/54 MB/s. I think it’s not a good idea anymore to buy a drive that’s limited to FW800 and USB 2.
  • The € 120 Toshiba 2TB StorE Basic (buy here or here). They claim it’s 119x79x17 mm but I think it’s 21 mm and will feature the 2TB WD SATA drive (15mm). They also have a slightly more expensive password protected version.
  • The brands I don’t like are verbatim (curved drives) and Lacie. Lacie (owned by Seagate) has the € 155 Rugged Triple 1TB. With software AES-256, USB3 (P) and FW800 (D,P).  I tested the Lacie Rugged 500 GB myself with FW and got 75/68 MB/s. They also have a more expensive an USB2+FW800 with hardware AES-128.
  • The G-tech € 190  1 TB USB3 + FW800 (D,P) G-drive mini is even faster: FW speed is 80/75 MB/s. G-tech is owned by HGST, which is owned by WD. Is it USB3 bus powered?
  • The $ 200 Gtech drive EV combines usb 3 and SATA (I think) in one device. It fits in their Thunderbolt enclosure. They claim speeds up to 135 MB/s over USB 3. I am pretty sure it has the Hitachi 7k1000 drive inside.
  • The € 73 Seagate Backup Plus Portable 1 TB with USM  and included USM-USB3 adapter. Unlike the WD, these colored drives are really ugly so only buy the black or silver ones! They even have disk that has both wifi and USM.

USM connector

Seagate has invented a nice USM standard, which basically is a SATA connector with a metal plate and a snap connection. This Universal Storage Module is now a SATA standard. Check my other post about the Seagate FreeAgent GoFlex system with USM adapters for all the different bridges like FW800 (Powered but NOT daisy chainable), USB3, eSATA and Thunderbolt. Seagate recently rebranded their USM line of products: now it’s called Backup Plus with a maximum size of 1 TB and maximum speeds of 5400 rpm (there are rumours about it being 7200 rpm in some pro models). The bad news is that they have dropped their 1.5 TB and their 7200 rpm drives.  The good news is that new disks all come with a USB3 connector. Later on they will add FW800 and Thunderbolt (the old GoFlex FW 800 I have adapters also works). I hope their new FW800 adapter will be daisy chainable. The $ 20 mele is a 9.5mm case USM and a USM-USB3 adapter.

The nice thing about the Seagate system is that they have a eSATA connector, but it seems like it’s not possible to get that anymore. I bought a standard eSATAp – SATA cable and found that the standard SATA cable will not fit in the USM slot! I had to take the drive out of it’s case to use it. Bummer.

I can also buy the Seagate GoFlex NET adapter and find out how fast that one is on Gigabit ethernet: it has two USM slots plus one USB2 slot. The one disadvantage is that it needs 12V power, but it’s easy to put it somewhere safe and undock a drive and grab a USM connector for on the road. This would give me the advantage of three very accessible drives in the house but the flexibility to use other connectors if needed. With the 500 GB Seagate GoFlex 7200 rpm drive I got 75/55. So to compare: I tested a 1500 GB Seagate GoFlex 5400 RPM drive with FW800 and got 65/55 MB/s.

Bare disks

The USM adapter will also connect to bare disks (you will need a cover that adds 2.5 mm to the bottom of the drive), I could even put them in the GoFlex NET adapter. And bare disks can also be used with standard cables like the DeLock eSATAp to SATA cable, or fitted into an enclosure later. I bought and tested  this cable: it’s a bit long but it works great!

See more about the bare drives in my post about internal 5 – 9 mm drives for my MBP here. There also is the 15 mm WD green 2 TB drive, but right now it’s pretty expensive. Note that some 7200 rpm drives might need to be powered by a USB Y-cable as they need more then the 4.5W that one USB 3 port provides.

It’s possible to buy a € 30 SATA FW800 dock, or a € 12 LC-Power LC-25U3-X USB3 enclosure that fits disks up to 12.5 mm or the nice € 22 ThermalTake USB 3 enclosure for disks up to 9.5 mm. Or I can buy this € 30 usb3 to eSATAp converter and these € 7 NewerTech ProtectaDrive sleeves or even $ 3 sleeves to protect them from static electricity. There also are a few really good multi-connector external casings for 2.5″ SATA drives, like OWC and Oyen Digital. Oyen Digital is the only brand that fits drives up to 15 mm. They have a good looking $ 40 USB3 + eSATA (ASmedia chip) enclosure  and a $ 70 FW800 (D,P) + USB 3 enclosure (Oxfort 944 chipset).

2.5″ RAID

Single HDD solutions will not make 150 MB/s video throughput.  The solution is either SSD (too small/expensive) or 2x HDD in RAID:

  • The $ 280 OWC 2 TB Elite Pro Dual Mini features FW800 (D,P), eSATA and USB 2 (Oxford 946 chipset). The enclosure only is $ 75, for drives up to 12.5 mm. Drive setup is RAID 0, RAID 1, SPAN or JBOD. 12V power.
  • The $ 350 G-tech 1 TB G-drive EV plus features both a SATA (which I hope can also be used with a cheap eSATAp and the Seagate USM adapter) and a USB3 connector. From their website: this drive keeps you on top of your game with accelerated transfer rates up to 250MB/s. I believe is a RAID set because it’s a bit thicker and it’s claimed speed is about 2x the speed of their normal EV drive. This might be the only RAID drive that is USB 3 bus powered. But it’s also as expensive as buying two 500 GB SSD’s.
  • Gtech also has the $ 449 2 TB G-RAID mini. This drive features both FW800 (D,P) and USB 3. They claim it has 170+ MB/s transfer rates over USB 3. I don’t like that it needs 12V power (no bus-powering over USB), that it has a fan and that the drives are not hot-swappable.
  • The € 419 CallDigit 2 TB RAID drive VR-mini. It has a nice screen for full configuration (JBOD, RAID 1, RAID 0)  and two hot-swap drive bays. Spare drives are € 175 per TB (this really high price includes a nice storage box). The VR-mini has FW800 (P,D), eSATA and USB2. The new VR-mini 2 has both FW800 and USB3, but no eSATA. Unfortunately, for eSATA or USB you’ll need 12 V external power. So it’s very expensive and not perfect.
  • Oyen Digital MiniPro 2 RAID looks like the calldigit but is much cheaper: only $ 260 for the 2TB version. On top of that, it’s FW800 (P,D), eSATA and USB3. You can also buy a $ 100 enclosure to fill it with your own disks (up to 12.5mm height), hot-swappable! And a nice screen for full configuration as well. They even have speed test results on their website: 82/77 for FW800 and 204/201 for USB3 (both with Hitachi 7k1000 drives in RAID 0, measured with Blackmagic). Strangely, for eSATA it’s only 153/202 (measured with AJA system test @ 16 GB), but this might be the 3 TB RAID 0 version (2x Toshiba 5k1500) as the USB3 for that setup is 125/204 as well (measured with Quickbench 4) . The only downside is that it’s raid 1 or raid 0 only, no JBOD. And that it needs 12 V power, so no bus-power over USB or eSATAp. How much for the spare bays?
  • The $ 80 Oyen Digital / OnnTo / DataTale RAID drive enclosure (looks like the OWC). Review here. This thing allows any two 2.5-inch SATA HDDs (9.5mm or 12.5mm) to be installed for JBOD, RAID 0 (Striping), RAID 1 (Mirroring) and Span RAID operation (RAID master GUI software). It features FW800 (D,P), USB2 and eSATA. The unit is bus-powered using the FireWire connection eliminating the need for a power adapter. And as it’s JMicron chipset only needs 5V, it can also be powered from the USB (DC to USB power cable) or eSATAp connector (special $ 15 cable). Unfortunately: no USB 3. The included power adapter is 5V/2A.

All use the Hitachi 7k1000 drives for maximum performance. None of them features USB3/eSATAp bus-power as most need 12V. The only option is the Oyen Digital DataTale that only needs 5V, with a USB Y cable it can draw up to 9W from two USB 3 ports.  One thing to keep in mind: the Hitachi 7k1000 drives need 5W (at 5V) for spinning up, so with two drives and a raid controller it might need a bit more power then the USB or eSATAp standard can provide.

If you want it to be USB bus-powered you will need to stick to two 2.5″ 5k drives: it’s not a coincidence that their maximum power draw is 4.5W (USB 3 = 5V/0.9A). I even came across a seagate 7k500 that was only 2.5W (USB 2 = 5V/0.5A).


Unfortunately there is no 2x 2TB raid drive that offers FW800 (D,P) + USB3 / eSATA, all bus powered. Maybe it’s just not possible yet.

So I bought the 1TB 9.5 mm my Passport and Seagate USB3 drives for now. I’d like to compare the WD (always encrypted) with the Seagate with and without software encryption (truecript). If software encryption is fast enough, I’d like to compare the seagate 5k1000 and the seagate 7k500 on both USB 3 and eSATA. Finally, I’d like to see if the HGST 7k1000 works on USB bus power and compare it with the 5k1000 disks. Then test it with the Oyen DataTale RAID 0 enclosure.

By then it’s around the end of 2013, the first 2TB 9.5 mm disk will be introduced, the SSD price will dive under 25c/GB and I’ll know if – and how I want it:

  • mac or win OS
  • exfat/ntfs/hfsj file system
  • internal/external drives
  • FW800/eSATAp/USB3/Thunderbolt
  • software, hardware or not encrypted

Update august 2014: OyenDigital has announced a FW800 (D,P) + USB3 + eSATA raid enclosure for 2×2.5″ (up to 15mm) hard disks for next month (with Jmicron chipset, so it might be 5V bus powered). Samsung has the spin point M9T: a 9.5mm 2.5″ 2TB 5.4kRPM disk with 32 MB on the market since november 2013: great choice, especially for bulk files. I can’t find it on the market but you could buy it at seagate (for instance the Backup Plus Slim or the Backup Plus Fast).


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