How to keep your data on a small removable SSD with USB interface?

The idea explored here is to separate your data physically from the computer that you are using them on. This has the following advantages: (1) you are quite safe from theft because you can keep carrying your data with you always, even when having to let your notebook at home or in a hotel because it is too heavy; (2) you can use your data on any computer (like a friend's computer when travelling, an Internet cafe computer etc.); (3) you can hand over data items quickly and easily because every computer has a USB interface.

You have to decide if the this idea is worth its benefits for you, as all solutions below are much slower and more expensive than a bigger standard SATA III SSD (as of 2014-06, about 100 EUR new incl. shipment for a 256 GB SSD, with data transfer rates up to 600 MB/s, though the continuous transfer rates have to the researched).

However, here are the solutions I could come up with. By adequacy for my requirements – which included to be 128 GB or more in size:

• SD card in SD card reader. This is the bes option on notebooks that come with a card reader, since it does not block any ExpressCard expansion port (reading your digital camera card is easily possible in the USB ports as well with SanDisk Ultra II SD Plus USB cards). However, it has to be tested still if the typical notebook card reader can utilize the speed of highest speed SD cards used here (else a ExpressCard/34 based card reader would be needed). Because for proper speed, we need the latest "U3" class SD cards. These are just being introduced around 2014-06, so prices will drop lateron. Currently available products:
  • ADATA Premier Pro 128 GB. Allows 95 MB/s read, 60 MB/s write, at least 30 MB/s continuous write as per UHC Speed Class 3. Possibly the only 128 GB SD card in that class so far. About 80 EUR.
  • Kingston UHS-I 64 GB. Allows 90 MB/s read, 80 MB/s write. However continuous transfer speeds are lower, but at least meet UHS Speed Class 3 (30 MB/s continuous write speed). About 94 EUR.
• SD card in ExpressCard/34 card reader. For data exchange, all readers can expose a SD card as a USB mass storage device, so no drivers on the host system are needed. The additional advantage of using a SD card is that you can also use them for other purposes (recording photos and HD video etc.). For proper speed, we need the U3 speed class cards again, see above.
• Compact Flash card in ExpressCard/54 card reader. This is a good solution, since the speeds of Comact Flash cards are comparable to the ExpressCard SSDs while the Compact Flash format makes it simpler to find an adapter to USB mass storage (namely, a simple card reader). However, Compact Flash does not fit by width into ExpressCard/34, so your notebook will need the larger ExpressCard/54 slot [see]. Speeds of Compact Flash are great, and for data exchange you can carry a USB card reader that exposes the Compac Flash card as USB mass storage (means it needs no driver). But high-speed, large-capacity cards are also expensive; recommendable products:
  • A moderately priced one is the Hama CF 128 GB (up to 150 MB/s read, so maybe 40 MB/s continuous write?) for about 145 EUR.
• ExpressCard/34 form factor SSD, plus USB adapter. This is the best option in terms of speed. It can be connected to other computers using a USB to ExpressCard adapter (overview; also see DeLock 61714 etc.). ExpressCard allows cards to use an USB 2.0, USB 3.0 or PCIe mode, and not all these adapters also support PCIe (the Digigear PCU10 does however, but needs manual configuration for PCIe mode). So check first which mode is used by the ExpressCard SSD – anything above 60 MB/s means USB 3.0 or PCIe mode. For the connectors etc., see the ExpressCard standards document.
  Available products 64 GB and larger:​

   

  • Wintec FileMate ExpressCard SSD 64 GB (165 MB/s read, 120 MB/s write)
  • Wintec FileMate ExpressCard SSD 128 GB (165 MB/s read, 120 MB/s write; about 150 EUR)
• Small "knobby" USB flash drive. If your notebook has a USB 3.0 port or you can add one via an ExpressCard/34 slot or similar, the achievable speed of this solution can be good, too. It seems that there is still no 128 GB flash drive in "knob" size. A hack to get over this would be to combine two of them physically so that they fit exactly into two adjacent USB ports on your notebook (and with a small cable-type USB hub to other computers' USB ports). Available options:
  • PKparis K'1 64 GB (140 MB/s read, 20 MB/s write)
• microSD card in "knobby" microSD card reader. This option works even up to 128 GB (with 128 GB microSD cards being available). However, these cards tend to be slow. Available models: just one so far
  • ​SanDisk Ultra microSDHC/microSDXC UHS-I card (30 MB/s read, minimum 10 MB/s write)
• Compact Flash card in 1.8" or 2.5" SATA drive bay. This is essentially using a Compact Flash card as a removable, rugged SSD. There are Compact Flash to SATA adapters for both 1.8" and 2.5" SATA SSD form factor (example: StarGat SAT2C). Also this solution will work only if your notebook can be modified in a way to allow drawing out the card from the HDD bay. And it's not really clear how the computer or operating system might react when extracting the Compact Flash card for example during ACPI Suspend mode. Also when using the system disk bay for this type of SSD, we cannot physically separate operating system and personal files as intended here.
• miniPCIe SSD in ExpressCard and SATA external enclosure. This is more a theoretical option since you do not want to handle a bare PCB with your data on it just to connect it to a computer that does not have an ExpressCard slot. But it would work, as there are converters for miniPCIe to ExpressCard and miniPCIe to SATA.