Testing methods

Our test bench for this flash drive roundup is a desktop computer running Windows 7 Enterprise 64-bit and consisting of an Intel Core i3-2100 CPU, ASUS P8H61-I (Rev. 3.0) mini-ITX motherboard with two USB 3.0 ports using an ASMedia ASM1042 USB 3.0 controller, 2 x 2GB Patriot DDR3-1333, one Intel 320 Series (G3) 80GB SSD, one Western Digital 2TB Caviar Green HDD, and one LITE-ON IHAS124-04 optical drive.

Iometer is a standard storage drive benchmarking software capable of testing mechanical, platter-based hard disc drives, flash-based solid state drives, and USB-interface flash drives. We provide a number of measurements for each drive. However, since the vast majority of users writes data to a flash drive, and then read off of it, the most important measurements for each drive are the sequential write and read speeds. While this might seem obvious, it should be noted this is different from a boot (OS) and application drive. OS/app drives typically do not see many frequent, sustained writes after initial installation. Furthermore, random writes/reads of smaller files are very common for an OS drive – this is where SSDs truly shine over mechanical HDDs, giving an SSD-based system spectacular snappiness compared to platter drive-based rigs. Random write/read performance is not particularly important for a flash drive unless it is being used as a ReadyBoost device. However, given how cheap DDR3 currently is, if you can afford a motherboard with USB 3.0 ports, you can afford enough system memory to not need a ReadyBoost drive! Furthermore, all of the USB 3.0 flash drives in this roundup are fast enough to support ReadyBoost in Windows 7.

That said, software virtualization applications like Ceedo, which act as a portable 'OS on a flash drive' certainly benefit from improved read/write performance, though thorough benchmarking and real-world performance tests of a program like Ceedo installed on a USB 3.0 flash drive are outside the scope of this article.

In addition to Iometer readings, we provide real-world usage scenario data for the drives. The first test writes 3,364 PDFs totaling 3.20GB from the SSD to the flash drive, then reads those same PDFs from the flash drive back to the SSD. The second scenario first copies 100 MP3 albums containing 1,133 files totaling 7.94GB from the SSD to the flash drive, and then those same MP3s from the flash drive to the SSD. The third and final test writes a single 4.16GB DVD image file (ISO of Fear & Loathing in Las Vegas) to the flash drive and then back to the SSD.

All drives were formatted to NTFS with a 4KB allocation unit prior to benchmarking, and all tests in Iometer were run also using a 4KB block size. While default file system and block size are variable between manufacturers, NTFS allows files larger than 4GB to be written to the flash drive (critical for DVD and BRD ISOs, among other file types), and it allows drives larger than 32GB to be used under Windows XP (unlike FAT32).


We were graciously provided the following samples by their respective manufacturers:

Kingston must have a die-hard Cincinnati Bengals fan on their design team!

Product Usable Capacity Price $/1GB
ADATA S007 32GB USB 2.0 29.8GB $44 $1.47
ADATA S102 32GB USB 3.0 29.2GB $50 $1.71
Kingston DT Ultimate G2 32GB USB 3.0 29.8GB $85 $2.85
Kingston DT R500 32GB USB 2.0 29.8GB $62 $2.08
Mushkin Ventura Pro 32GB USB 3.0 29.4GB $75 $2.55
Patriot Supersonic 64GB USB 3.0 60.5GB $150 $2.48
Patriot Supersonic Magnum 64GB USB 3.0 58.9GB $196 $3.33
Super Talent Express DUO 16GB USB 3.0 14.6GB $28 $1.92
Super Talent Express RC8 64GB USB 3.0 51.2GB $145 $2.83

These are the prices as of the time of this article's writing, and are absolutely not static. Be sure to keep this in mind when determining their comparative costs and considering their bang for the buck. As you can see, the USB 3.0 drives have a wide dollar per GB cost, from ADATA's S102 at $1.71/GB to Patriot's $3.33/GB Supersonic Magnum. Find out how these flash drives performed on the next few pages!

Introduction: A Brief History of USB Flash Drives USB 3.0 and 2.0 Flash Drive Native Interface Write Performance
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  • BadThad - Monday, August 1, 2011 - link

    Good job, nice little test!

    For my purposes a simple 4 or 8MB USB 2.0 drive is fine. Most of the files I need to move around are small and it's only a couple of seconds for read/write ops. As often as I lose these or they just outright die, I can't see spending more than $10 or so on a flash drive.
  • 7Enigma - Monday, August 1, 2011 - link

    I assume you mean GB? :) And I'm with you there. I have an 8GB and only occasionally wish I had a 16 or 32 and most of the time it's because I'm too lazy to remove unneeded data.
  • casteve - Monday, August 1, 2011 - link

    Thanks for the review. I use thumb drives for archiving data. Create a ZIP or RAR file and place it into a truecrypt folder. With USB 2.0, it's faster to compress using the internal drive and then transfer onto the external drive's truecrypt folder. With 3.0 thumb drives, maybe the transfer rate is fast enough just compress on the fly. It'd be nice to see this proved out.
  • epobirs - Tuesday, August 2, 2011 - link

    I've got a Corsair Flash Voyager 16 GB USB 3.0 unit. They've been down around $20 or less AR recently. It's definitely faster (and about 33% longer physically) than its USB 2.0 equivalent but I wonder it would have fallen in this lineup.

    I carry a bunch of drives for my job and have been retiring 8 GB and smaller units and replacing them with 16 GB models now that the cost per gigabyte is the same, around $1, in promo specials. The Corsair is enough faster that I'll now buy only USB 3.0 drives as good deals appear, preferably 32 GB models.

    I might be satisfied when I have a dozen terabytes in my cargo pants pocket but I won't know until I get there. My definition of a decent software and video library to take with me everywhere keeps growing and the cloud does not strike me as a reliable substitute yet or possibly ever.
  • jagaimo - Wednesday, August 17, 2011 - link

    USB 2.0 has a maximum bandwidth of 480Mbits/s, or 60MBytes/s. On a good number of these benchmarks, even the USB 3.0 parts don't hit that speed.

    e.g., 100MB Sequential Write Performance - Native Interface. The Adata S102 32GB USB3.0 unit only hits 38MB/s. It's still short of the USB 2.0 speed limit.

    I guess my point is this... The 480Mb/s bandwidth of USB 2.0 isn't the limiting factor. It seems like it's something else. Is there a reason why we don't see 60MB/s transfers on the 2.0 devices?
  • MGSsancho - Tuesday, September 6, 2011 - link

    That's 640mbs total in both directions. It is really 320mbs in each direction.
    http://www.usb.org/developers/docs/ see the specs
  • jonathan1683 - Saturday, September 17, 2011 - link

    I would have liked to see 32 GB ones in the mix, but they might be in another article. I have a 16gb flash voyager and it always takes forever reading it initially. Sometimes a couple minutes just to initiate a directory listing. Does anyone know if this is common or maybe I have a defective unit? I notice I don't have this issue on windows XP it's only on win7.
  • tkafafi - Tuesday, March 20, 2012 - link

    I think the writeup did a great job of providing the experimental data. I'm just wondering what is the explanation for the results seen on the mixed usb2/usb3 systesm, as they were surprising for sure.

  • j7n - Friday, September 20, 2013 - link

    Early USB flash memory wasn't "agonizingly slow" in comparison to floppies and rewritable CDs, especially if you account for the time needed to verify the recording on those discs because they were so unreliable. A USB 1.1 port could practically do around 600-700 kB/s, which is at least fifteen times that of a floppy.
  • hizoka - Thursday, December 26, 2013 - link

    Silicon Power USB 3.0 Flash Drive, Read/Write Speed Up to 90/60 Mbps
    16 GB 10.99 $ FREE Shipping
    32 GB 19.99 $ FREE Shipping
    64 GB 35.98 $ FREE Shipping
    in Amazon

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