Review: Kingston DataTraveler G4 128Gb USB Flash Drive

When I first tried my “crazy” SSD in a USB External Enclosure experiment, USB memory sticks were paltry in size and performance. While such a solution wasn’t exactly compact or convenient like most USB keys, it did offer the capacity and performance I was after, at a reasonable cost. Even today, I have little qualms about that solution – it hasn’t skipped a beat at all!

But then, I got tempted. My eyes caught on the Kingston DataTraveler G4 128Gb USB Flash Drive, for AU$75. That’s not bad for price … but the size of it was more like the regular USB keys. Intrigued, I opened my wallet and now I’ve got one for testing!

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The drive was in “classic” regular Kingston packaging, making no loud claims of its performance at all. It did advertise USB 3.0 connectivity, which is considered a “norm” now, as well as a 5-year warranty. The rear indicates the unit was originally was intended for Russian distribution by the RU lettering, but has been adapted for Australia by the inclusion of the mandatory warranty rights statement.

While Kingston drives still have the AC and LK numbers, the Kingston site no longer accepts these numbers for verification of the genuine status of the drives. As a result, we turn to a secondary form of verification which is the “holographic” sparkly coloured printing on the drive in the capacity line.


Indeed, this one is sparkling, so there’s a fair amount of confidence that it is genuine. The 128Gb key has a green ring at the back – the colours indicate capacity for this particular series. The front is a pretty clean design, as is the rear …


… which is adorned by the moulded Kingston logo and the CE mark. The cap itself detatches completely from the drive, making it a candidate for getting lost, although it does slip over the rear ring section provided you’re not already using that.


DSC_6410The unit itself is solidly built, and doesn’t seem to come apart even with many suggestive prods. Unfortunately, that means no teardown :(.

There’s nothing else in the package, as you would expect for a “value” line USB key, but lets see how it performs.




Performance Testing

drive-winxplorThe drive comes pre-formatted as a FAT32 drive with KINGSTON as the volume label. The usable capacity is seen below. Do note that if you choose to format it with Windows, by default, it will not offer you FAT32 as an option. You will only be able to format to NTFS or exFAT without using third party tools or other OSes.


The drive was tested in the original formatted configuration with CrystalDiskMark on my regular Gigabyte 890FXA-UD7 + AMD 1090T BE + NEC USB 3.0 controller + Windows 7 x64 based system.


The drive’s sequential performance makes good use of the USB 3.0 capabilities of the controller, however, the write performance diminishes quite quickly as the block size decreases. You can see, the write performance is exceptionally poor for both 512kB and 4kB sizes. This implies that this uses NAND flash parts with large block sizes and incurs penalties for small writes.

It’s probably not a USB key to choose if you intend to back-up many many small files, as it’ll be slower than even the Kingston DataTraveler 100 G3 32Gb by a margin! But as a key for reading from, it’s not bad.

We can explore this in further detail with ATTO.


It seems clear that the drive’s write performance leaps as soon as we hit 64kB transfers, which implies it may be using 64kB sized flash blocks. The read performance steadily increases as the block size increases, likely related to the latency of the controller and USB 3.0 subsystem in general.

A test with H2testW revealed no errors in filling the entire drive and verifying, and neither did a manual fill and checksum. However, it did take quite a long time to fill the USB key.


Of course, here’s the HD Tune sequential read result as well …


While I didn’t take the drive apart, the firmware reported by the drive was PMAP, which highly suggests this is based around a Phison controller, as most of their lower-end DataTraveler series have traditionally been built around. PMAP is the default firmware revision ID for Phison controllers.


The Kingston DataTraveler G4 a relatively cheap 128Gb USB Key, which signals the introduction of large size USB keys as “mainstream”. It’s got rather simple, clean aesthetics with a basic cap which can be misplaced. It operates as expected, although it gives you a little less storage than you’d expect (about 125.7 “weasel” Gb).

Unfortunately, it seems that it leverages a rather basic controller, with large block flash memory, which puts it at a penalty when dealing with small files below 64kB. This is a common trade-off with larger capacity “basic” USB keys. The performance really isn’t anything spectacular, but for bulk large file transfers, it could be very acceptable.

Where you are making many small file back-ups of documents, the performance could be slower than the USB key you’re already using, and is unlikely to matter whether that’s a USB 2.0 or USB 3.0 key given the rates are very far below even USB 1.1 rates (~1Mb/s).

I look forward to the future where SSD-grade performance can be found in small USB keys at a mainstream price, but for now, people chasing performance should probably look elsewhere.

About lui_gough

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4 Responses to Review: Kingston DataTraveler G4 128Gb USB Flash Drive

  1. sury suryanaraynanan says:

    While transferring a lot of small and medium files, often the datataveler was ejected, especially when it was around a few hundred MB files. I am not computer savvy. I use a Mac Pro. Is there a reason and solution, please?

    • lui_gough says:

      Maybe it has to do with the contact on your USB port. Try cleaning it using a blower bulb. If not, also try using a USB extension cable as it may have a better contact. If that still doesn’t resolve the issue, it may just be down to a compatibility issue with the Mac – try using the USB key on another non Apple machine. If it continues to fail, you may just have a defective or faulty unit.

      – Gough

  2. John nu says:

    We have been using a lot of these to put image builds on, so far 7 out of 11 have now become useless. the sticks are now not even readable!!! so having to find something a lot better than these

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