Sunday, September 2, 2018

Which Flash Drives Are Best for Backup?

The most appropriate form of backup depends on the type of threat to the files. For example, a permanently-connected hard disk backup drive will protect against failure of the primary disk drive, but not necessarily against fire, flood, theft, viral infection, ransomware, you get the idea.

Online backup protects against most of those but it can be painfully slow and, in my own experience, may fail when recovery is required.

I do create monthly backups on archive-quality Blu-ray M-Discs, and keep those in safe places, but would like something more frequent and current.

How about a nightly flash-drive backup that I can carry with me if I like? Below are tests of some drives. All prices are Amazon Prime:

Corsair Voyager Vega (CMFVV3-128GB) USB 3.0 128GB Ultra Compact Low Profile Flash drive $53.99

Of the drives that I tested this is easily the best, though also the most expensive. I like the very small size, making it perfect for a complete backup that can be carried inconspicuously in a pocket, a wallet or purse, briefcase, shoe, wherever. A bright little blue activity light flashes during data transfer. The drive seems to get a little warm during transfer, but not hot.

Using a USB 3.0 port, the flash drive writes data at about 432 megabits per second (Mbps), which is about 9% of the 5,000 Mbps USB 3.0 standard.  My recent backups are 25 zipped files running about 77 GiB (82.6 GB) total, and the transfer is completed in about 25 minutes.

Using a USB 2.0 port with the same drive, the write speed is about 205 Mbps and the whole task takes about 54 minutes, more than twice as long as when writing from a USB 3.0 port. Maximum theoretical data transfer speed for USB 2.0 is 480 Mbps, so the flash drive is actually writing at 43% of theoretical. Not bad, but I'll stick with USB 3.0.

Lexar JumpDrive S75 (LJDS75-128ABNL) USB 3.0 128GB $33.29

Second in price, second in performance.  This flash drive has the same 128GB nominal capacity as the Corsair, but is physically much larger (see image), the largest I'm testing, and far from wallet size. Using USB 3.0 it writes at about 293 Mbps and finishes the 77 GiB job in about 37 minutes. It doesn't seem to get warm. It does have an activity light. If size is not an issue, it's a less-expensive alternative to the Corsair and about 2/3 as fast.

Patriot Tab Series Micro-Sized (PSF64GTAB3USB) USB 3.0 Flash Drive, $17.99 for 64GB, no 128GB version currently available.

Though it hardly seems possible, this drive is even smaller than the Corsair. It doesn't get hot. It has no activity light. The 64GB version can't take my entire backup, but a transfer of about 40GB yielded a write speed of about 169 Mbps, or 21 MB/s.

Sandisk Ultra Flair USB 3.0 32GB (SDCZ73-032G-G46) Flash Drive High Performance, $29.99 for 128GB.

This drive is a big disappointment. I previously held Sandisk in high esteem, based on prior experience, but this drive is WAY over-hyped. A lot of ballyhoo about high-speed USB 3.0 performance (even in the name), but it heats up and actual performance falls off dramatically after a minute or two. A 24 GiB transfer achieved a rate of about 166 Mbps, finishing in a little over 20 minutes. Lots of marketing, not so much product. It might be OK for some applications, but not for this backup. By comparison, the Corsair finished the same 24 GiB task in less than 8 minutes.

It gets hot to the touch when writing, and warm even when idle. No activity light. Note: Testing was done on 32GB models, not the 128GB model. I believed the hype and bought several, but they perform badly and I won't be buying anything more from Sandisk. Ever.

Testing platform:

The computer used for these tests is a two-year-old ASUS H170-Pro motherboard with an Intel i7 6700 3.4 GHz Quad-core CPU and H170 chipset running Windows 10. Five USB 3.0 ports and two USB 2.0 ports are available at the front of the system. The C: drive is an SSD, but only 4GB of the backup data comes from C:, the rest coming from Seagate SSHD hard drives on SATA 6.0 Gb/s ports.

More about the backup:

All of the tested flash drives are bootable on this system (and several other systems). In particular, they are intended to be used as Macrium Reflect Rescue media, with backup files then written and rewritten to them as desired.

All are USB 3.0. In my opinion, USB 3.1 is an unnecessary enhancement in a backup application unless the destination drive is actually able to write at speeds of at least 1 or 2 Gb/s, and no flash drives are that fast yet. Be wary of the 3.1 hype.

Read speed was not measured on any of the drives. They are backups, and if all goes well I will never have to read from them except very occasionally to verify that they are written correctly.

Prices are what I actually paid, and may change at any moment, most likely down.  This technology is moving fast, and no doubt new devices will soon make these obsolete.