26 July 2015, Comments: 23

 July 2015         Ian Chiu

Sandisk Ultra Fit’s speed, low-profile and price range comes out on top in comparison with other tested mini USB 3.0 drives. At only 27.4 cents cost per gigabyte (64GB, Feb 2016), the Sandisk is one of the least expensive mini drives available for 64GB. Combine that with compact form factor and speed, and you get a nice plug-it-and-forget-it mini USB drive.

Feature Comparison

As new products hit retail, we will add them to this chart so you know how current batch of mini drives fare against new ones.

DT Micro 3.1
Ultra Fit
Silicon Power
Jewel J06
JetFlash 710
Mini Metal
Strength:DurabilitySpeed, size, priceDurabilityRetractable plug
Read Speed:102.21MB/s135.75MB/s109.66MB/s90.13MB/s89.17MB/s
Write Speed:15.65MB/s31.77MB/s15.56MB/s28.83MB/s35.30MB/s
Storage:16 - 64GB16 - 128GB8 - 64GB16 - 64GB16 - 64GB
Interface(s):USB 3.1 Gen 1USB 3.0USB 3.0USB 3.0USB 3.0
Dimensions:25 x 12 x 4.5mm19 x 16 x 8.8mm24 x 16 x 8.5mm22.4 × 12 × 6mm27 x 16 x 6.4mm
Build Material:Aluminium unibodyPlastic grip, aluminum bodyPlastic body, plastic coverAluminum unibodyPlastic body, aluminum cover
Color(s):SilverBlackBlackGold, silverSilver
Release Date:July 2015August 2014July 2014Dec 2014Sept 2013
Warranty:5 years5 yearsLifetimeLifetime5 years

 Benchmark Analysis

During our large file (a single 4.7GB MKV) transfer tests, the Ultra Fit managed to maintain an average speed of 135.75MB/s and 31.77MB/s during read and write tests respectively. It bested the competition in all read tests by a large margin while it was only outpaced by Verbatim in write which posted 35.3MB/s. Both Sandisk and Kingston did reach their claimed speeds. The other three manufacturers, however, don’t advertise their speeds so your mileage may vary. In another test which involved copying back and forth 4.7GB JPEGs (most being between 4 and 8MB), the Sandisk outperformed all others with the exception of Verbatim, whose write speed was about ahead by about 5MB/s.  Neither write nor read speed was close to its much faster sibling or any other full-sized USB 3.0 flash drives for that matter but surely you know you are trading speed for size. Note these two tests were selected to reveal the drives’ USB 3.0 performance because we felt most people would rely on a mini drive primarily as intermediary or secondary storage for media data.  Applications require efficient random access which these drives – without a decent controller – wouldn’t do a good job at. Lastly, all drives were re-formatted into exFAT for the 4GB file transfer benchmark.

 Design & Build

The Sandisk sports a minimalist design with a length of only 19.1mm while still able to accommodate a tiny LED activity light. Its size is fairly close to Logitech’s nano Unifying receiver if you have one available. When plugged, the Ultra Fit only protrudes just 8mm from the edge of a laptop, and its curved shape also makes it easy to unplug despite its diminutive size.

Tested USB 3.0 drives are all fairly small until you put them side by side. When they are next to each other, the Sandisk’s size compares favorably to others. The reason being that all the other drives come with a loop hole to attach to a keyring, and this adds to the drives’ length considerably. The Verbatim is even twice as large as the Sandisk, largely due to its retractable connector mechanism. In terms of durability, Kingston and Transcend both share a rigid aluminium unibody, which is likely to survive if it’s being stepped on.

Physical size comparison

Overheating doesn’t seem to be much of an issue as far as we can tell. The Transcend did get a little bit warm after our endurance tests but that’s simply because the drive’s aluminium conducts heat faster than most other materials commonly used on flash drives.

 Cost per Gigabyte

These prices were taken from Amazon directly, and are up-to-date as of early April 2016. And judging from current prices, there’s no reason not to pick a drive smaller than 64GB or even 128GB.

DT Micro 3.1
Ultra Fit
Silicon Power
Jewel J06
JetFlash 710
Mini Metal
16GB54.4 cents43.7 cents58.3 cents43.8 cents61.6 cents
32GB37.5 cents31.2 cents45 cents34.3 cents68.7 cents
64GB41.1 cents24.9 cents38.8 cents31.2 cents58.3 cents
128GBn/a23.4 centsn/an/an/a

 Who Would Need Such a Small Drive?

Buyers who want a drive that only protrudes as little as possible from a USB port should consider one. Thumb drives in general stick out quite conspicuously so they could easily get bent when being bumped repeatedly. This could easily result in data loss and maybe even worse, a broken USB port. Compact drives by design can always stay inserted to a USB-enabled car stereo or to a notebook as a semi-permanent storage for media. They can free up precious space on the laptop’s speedy SSD for mission critical tasks. For this reason, a tiny drive can actually prove to be quite practical to some of us who might need an effortless storage expansion option.

Mini USB 3.0 Drives on Amazon

  • Jo-han Goh

    Finally a new posting. I thought you guys forgot the website entirely

    • everythingusb

      Thanks for your comment. We are reviving the site after a 4 month long hiatus. Past evaluations of the site suggested a new editorial direction is necessary. This article is the first step in this direction.

  • One review of the Sandisk on B&H complains it runs too hot, something I have also experienced with previous generations of the design.

    • Sopot

      Apparently so does the Transcend. Sad really, I need a reliable small usb 3 stick.

      • Even larger drives (including the new Samsung 1TB USB SSD) seem to have that issue. The thermal dissipation on a usb stub-sized drive are never going to be enough, and market volume is not sufficient to justify the development of ultra-low-power controllers and NAND flash to minimize TDP.

        On the plus side, heat actually improves the reliability of NAND flash.

        • Nino Martino

          Hi Fazal, do you mind to tell us more about how the heat improves the reliability of NAND flash? I really am interested to know more about it

        • P Cox

          From your reference: “The modification is a complex one and required substantial engineering, but the results are impressive—a brief and restricted jolt at 800C appears to “heal” the flash cell, removing its retained charge. Macronix estimates that this can be done repeatedly as needed, leading to a flash cell that could potentially last for 100,000,000 cycles, instead
          of the roughly 1,000 cycles that current 21nm TLC flash cells are rated to last.”

          My guess is that the flash drive isn’t receiving a “brief and restricted 800*C (1,472*F) “jolt”” in the USB socket of your computer; if it is – then it probably doesn’t matter if the USB flash drive life is extended.

    • yeah this is why I am here looking for a replacement, the 32GB sandisk ultra fit I have gets WAY too hot for me to leave it the laptop permanently… this laptop does have a microsd slot, might get one of those instead (well as long as it can boot, which might be unlikely, oh well, figure it out eventually)

  • 2ool

    I just bought Sandisk Ultra Fit, and it seems overheat fast while copying 20GB file. which make it disconnect without complete copying.

    • everythingusb

      Hmm… I tested the Ultra Fit on Surface Pro 3 and MacBook Pro Retina (late 2013). Before completing these benchmarks, I repeatedly filled up the drive with my 40GB photo library. But I never had an issue with overheating let alone disconnecting on its own prematurely. Could you tell us more about your problem?

      • 2ool

        I have the 32GB model. and I tried to write (copying from local drive) one single file 20GB*. the write speed was 47MB/s ~ 30MB/s. but the drive become extremely hot for touching after 1 min of writing , then it disconnect. I tried this on different format i.e. NTFS, exFAT.

        I was able to write the file on USB 2.0 without overheating. also I did tried to write the same file on USB 3.0 while pausing the process if the drive become too hot.

        The drive didn’t seems to have issue reading the same file to my PC (copying it to local drive)

        I believe this issue has relation to the drive and the type of files (not my PC).
        *20GB was Guild Wars 2 Dat file.
        *sorry for my bad english

    • hsk

      I have bought the 128GB version of Sandisk Ultrafit and it does get quite heated when copying larger files or even when you leave it in the laptop for 3-4 hours.

  • Arthur Hortmann Erpen

    Can you have two Sandisk Ultra Fit plugged in a Macbook Pro at the same time? Are they small enough?

  • Lol, this is exactly the flash drive that I owed. It is different brand though. Alpha USB, I am talking about the large one on a picture. It lasted for over 5 years until it fell under my car wheel :) I never understood why someone would want to buy such a tiny USB Drives as these examples. They are so inconvenient and easy to lose. This is the model I have, it is not large and not small, I think such size is perfect and there is no need to make smaller.

    • David Ploenzke

      Because you can leave them plugged in for extra storage.

  • RinconBlue

    I have one of the Sandisk drives and I got a similar sized Leef drive. The Leef drive has an LCD activity light which illuminates the entire drive vice the small light on the Sandisk. I haven’t benchmarked them but they seem to be about the same speed.

  • Jakewwa

    What makes one drive faster than the other? The all have the same USB 3.0 interface. Do they use different memory? The controller? What??

    • tipoo2

      Yes, controller and NAND. USB 3 is just the interface. If they had a 1TB/s interface they’d still only read and write at ~130, the bottleneck is elsewhere.

  • Alessio Brabus

    Hi, forgive my bad english. Interesting test, but what about random 4k read/write? I need a fast USB drive to enhance storage capacity of a lenovo Yoga 300 (just 32gb, only 1 free! How they can sell that unusable thing?)) I tried a Kingston Hyper X, it’s very fast in sequential read/write, but very slow in random 4k, and even too large for a plug in and forget drive. The Sandisk Ultra Fit has perfect size, but it’s slower in sequential performace compared to the HyperX, so I think it’s even worse in random 4k. :(

    • tipoo2

      I’m curious about this too. Large sequential transfers are easy, how is it at high IO tests and 4K random read/write?

  • Robert Baker

    First for those asking why such a short USB stick – I am a teacher using a school computer for over a year and half and I need something that I can take everywhere on campus and to home. I keep everything for my class and extra curriculum activities on my drive. This allows me great flexibility with data and convenience to be completely mobile. If I have a regular USB drive sticking out it would get destroyed in a short period of time and that is real experience. Second to the best unit I have found has been the Sandisk Cruzer Fit USB 64 GB.. It has preformed flawlessly and allows for everything I need to be mobile. I highly recommend.