Wednesday, July 04, 2018

A Faster USB Key

After more than four happy years of using my Sandisk Cruzer Extreme USB key  I recently tried to trade upto the 128GB Sandisk Extreme Go key.

To my astonishment my 2014 Cruzer drive managed a sustained 120MB/second plus read or write speed,  the 2018 replacement was stuck at less than 90MB/second.

Do you really need it?
In a home environment Marcus rarely uses any USB key, instead  a wired 1GB network provides a healthy 100MB/second point to point data transfer.  

Our Wireless networking is a little slower but still at least 60MB/second.    Overall either is quicker than transferring files to a key, walking to a destination computer then reading them back,

But in 2018 our increased mobile lifestyle has meant frequent use of USB keys to move typically around 20 GB data segments.    So yes, a faster drive might help

When Money is no Object

Dell currently offers a 500 GB and 1TB Thunderbolt 3 SSD

Whilst this can obtain a 2500MB/second plus burst rate there are a couple of notes I would make   (Windows Central review )

- It requires a computer with a Thunderbolt 3 port
- I mean a USB-C physical port on which there is also Thunderbolt
- The device has a fan (but needs no external Power)
+ It is beautifully small
- But sealed
- It is very costly
---  It needs connection via a USB-C to USB-C male to male lead.   And thus it's only a matter of time before you forget it and get really totally and utterly cross.

Marcus's Alternative Plan

- I did quite a lot of research on enclosures that might hold M.2 SSD disk drives
- At time of writing there was no sensibly priced enclosure that would take a M2 type M key aka NVMe PCI express key
- So at best you can get an enclosure that supports the SATA protocol M2 type B disks, and this obviously limits you to SATA 3,  600 MB/second
- In fact further research showed most enclosures accomodate the M.2 Type B drive but then require a cable to connect it to a computer.

As above I feel this is a terrible idea

Brilliant Plan: Silverstone MS09 and Samsung 860 EVO

Finally it is mounted.  

And now my troubles just began ....

A cunning Plan Goes Wrong

After 5 minutes of trying to put the SSD and electronics into the case and failing I got out my digital Calipers.

 Width of the SSD is 22.04 mm

 And it needs to rest inside a channel 21.95 mm wide.   Hmmm.

SSD Trim Function

Since this is Switzerland and Computer companies point plank refuse to take back goods it was time for a gamble.


 If you look very carefully (click on any image to enlarge) you will see there is a slight recess on the sides of the Samsung M2 disk.

If I can just shim down the width using sandpaper ....

And now it magically fits.

Some Performance Figures Then

I also introduce the benchmarking world to my now established friendly large testing file ... Centos, the Linux distribution.

 Copying on a USB 2 port is obviously painfully slow!

Note that all tests are performed without Windows write caching.  I want to be able to simply pull the key out after files are said to be copied and not have to manually eject.

In my tests NTFS, exFAT and ReFs disk formats all performed about the same.

I found out that using Windows Copying or my old skool favourite Total Commander I got about  280MB/sec plus sustained.      If I used a Benchmark took I got more,upto 400MB/second,  but this was not the actual copying time in practice.

Also I had reports that the speed slowed down after 20GB copying.  So I made a 32GB file and I am delighted to report that for me there was no slowdown in my testing.

Technical Info

And So
Yes, I now have a 250MB/second real world fast, USB Key with a 500 GB capacity, at less than half the cost of the albeit much faster Dell, Thunderbolt 3 key.

My total outlay was about 200 CHF which is about 150 GBP.

And my drive has a standard USB Type A connector, requires no fan, and is even smaller than the Dell unit.

I am happy!