A number of years ago I bought a 128GB micro SD card from ebay at what I thought was a very good price - a 'too good to be true' price! and of course it turned out to be a fake. After some simple testing I found it was a 64GB masquerading as a 128GB.

Just the other day I was looking through AliExpress and I came across a 16TB USB3 Pen drive, and again at a 'too good to be true' price of just over 11. This reminded me of the the micro SD card so I couldn't resist buying one to see if it truly is 16TB - this cappacity is bigger than my entire NAS and backup drives added together. If it actually works as advertised I would give it a try initially as a second backup to my NAS.

So this is the advert and it looks a nice piece of kit:

The drive arrived by post in just nine days. First impressions - well it arrived in a USB cable bag with a sticker labeled 16T but it has a good quality feel to it and weighs in at 17g.

Using a Windows 11 laptop I plugged in the drive and it was recognised and assigned the drive letter D:. I tried to copy a file to the drive and immediately I had these errors.

Reinserted the pendrive and giving it another go I copied a directory that had 1.44GB of data. This time it transferred without problems. On checking the properties it can be seen that the 1.44GB takes up 3.4GB of disk space. I put this down to a large sector size and dozens of small files (a little more on this later).

With that success I copied a series of large files and it can be seen that large files take up the same disc space. I then continued to add files to the drive to around 212GB then stopped for the evening.

The next day I plugged in the drive only to find my test6 folder empty. Over the course of the next hour the other test folder contents started to disappear, the used data on the drive remained unchanged..very strange behaviour.

It was time to reformat the pendrive. I selected exFAT with the smallest sector size of 1024 Kilobytes (default 4096) hoping it will help with the disc space/file size issue..

Copying the directory containing the small files (contents have changed) resulted in the data size of 1.3GB and 3GB on the drive..much the same as before so the small sector size made no difference. Not what I was expecting!

The following pictures show the properties of the drive, the first with 135GB used space and the second with the directory contents vanished. In fact four of the five directories have lost their enties.

After the failure using the default format of exFAT I re-formatted the pendrive to NTFS. I then copied my 1.45GB directory filled with small files which transferred without any problems. The data size also matches the disc usage space.

I then copied a directory containing 528 files/305GB which looked as if it copied correctly..

Until I looked at the directory properties - 380 files 204GB..a lot of lost data!


Well, it was too good to be true. With exFAT I hadn't copied more than about 220GB before the directory entries started to disappear and after re-formatting (exFAT) it did the same thing. I also tried NTFS with slightly different symptoms but the same results of data vanishing so for the moment don't spend your money on these devices as they are not what they purport to be.

More testing is required to see what the pendive actually is and whether it has USB3 or USB2 data transfer rates. I might crack it open but it'll have to wait until I get my workshop back up and running.