USB 3.0 Transfer Speed with external memory devices

We have disussed SSD's in detail in this thread

https://www.printerknowledge.com/threads/which-ssd-to-buy.13327/page-13#post-115624
focussing on speed, capacity, technology, health etc; I would like to add some info about using such flash/SSD memory devices.

About all computers - desktop, notebook etc come with USB 3.0 connections - 1 or more, or with a smaller USB 3.1/type C connector, and the USB standard is evolving to higher connection speeds and adding more complex setups for the supply of power to the connected devices or charging the notebook at the same time. It may not all work as the USB standard implies, I just like to have a look to the effective transmission speed to yan get with various devices and types of connections.
I'm using a Samsung 850 EVO 500G SSD for some tests, this drive runs at 450/420MB/sec R/W in my desktop computer on a SATA connection, the computer is pretty old, I take these numbers as a reference for further tests.
I'm using the Atto DiskBenchmark software for the test of the transmission speeds with these settings


Much higher values of the I/O and file sizes are possible, but these settings already show how the speed is leveling off in the Megabyte range; I just do one cycle for these tests (the diagram shows the speed of a notebook I will refer to later)
Connecting a SSD to a dektop computer is one thing, a few cables to the mainboard and that's it.

If you want to use a SSD for portable use, or connecting it to a notebook, via the USB 3.0 port, you need an adapter SATA to USB 3.0 or 3.1, some adapter like these



The all have a SATA connector on one side and a USB 3.0 connector on the cable, with a blue plastic insert in the connector, power is delivered via the USB connection to the adapter electronics and the SSD drive. All adapters come from Far-East - Ebay or Alexpress or similar, there are no signs and indications for the actual manufacturer, no name, partnumber or else.
The above Atto test diagram shows how my notebook is performing on the USB connecctions, I'm using a M.2 SSD card in a small external drive case with an USB connection and I get 500/420MB/sec R/W speed which is pretty good for a 12" 200€ notebook.

When I now connect the above Samsung SSD via the adapters to the USB port I get these numbers - from left to right 33 - 58 - 120 - 250 MB/sec for the reading speed , a huge variance between these adapters.
You just don't know what you get when you order such a SATA to USB 3.0 converter, the product description does not tell you, the seller just promises USB 3.0 speed so you can be happy if you get a speedy version or you feel cheated with a fake USB 3.0 converter. I argued with some suppliers about that, with some limited success, it's just 5-10$ items, and some suppliers did argue for weeks. the problem is with Ebay or Aliexpress that the transfer speed is not part of the product description so you cannot just claim that the product does not meet the spec/description.
Please let me continue with some other USB hardware in the following posts.

I got another SATA to USB adapter delivered yesterday from Hongkong, a model which looks pretty similar to those I already have, but this one runs faster than any others so far, it does 450/390 MB/sec R/W with the Samsung EVO 500G on my notebook which is the best speed of all and probably about the limit this type of interface connection can do. It is this one
https://www.ebay.de/itm/SATA-Kabel-Sata-Zu-USB-Adapter-Konverter-USB-3-0-2-5-Zoll-22-Pin-Hochste-6-Gbps/253843842804?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=20160908103841&meid=3bbc2ca4d6864aa282fc6ae43cbda770&pid=100227&rk=3&rkt=13&mehot=ag&sd=263696424552&itm=253843842804&pg=2054502&_trksid=p2054502.c100227.m3827
I'll order some more and scrap all my older and slower adapters once they arrive.

Notebooks, specifically smaller ones, just come with a low number of connection possibilities - 1 or 2 USB ports, a HDMI monitor connection and a sound and a power connector. Business notebooks in a much higher pricing and performance range offer more, and additional docking stations and port extenders.
If you use a notebook somewhat stationary you wan to connect various peripherals to it - printer(s), scanner, mouse, card reader, some external drives etc. So there is no way around a USB hub; there is a wide range of (claimed) USB 3.0 USB hubs available at Ebay, Amazon etc but no seller tells you anything about the actual transmission speed, it is the same dilemma as with the SATA converters.

This is just a small collection of those, all without an actual brand name, the module on the right side is an external case for a M.2 2280 SSD module with an USB 3.0 connector, this one reads at 500MB/sec as per the test diagram in the above posting. The middle and the bottom hub run at 30 and 50 MB/sec resp with this flash memory, cutting the speed down to 10%, the small silvery one runs at 90MB/sec. The only exception is the left hub, with the switches per connector, this one let the SSD run at 490MB/sec, basically at full speed. I have more of such poor performing hubs, they all kill the speed of external disks and SSD's significantly. If you use an external disk for backup purposes it makes a big difference until the backup is finished, you don't want to wait for half a day until it is done. This hub with the switches come in a 4 or 7 connector configuration and is offered with or w/o an external power supply. I recommend strongly an external power supply for the hub as soon as you connect multiple SSD's to it or an external HDD which can pull up to 1 Amp. I have a few more of these hubs on order and will scrap all other slower ones in my hardware collection except the small silvery one.
So be aware that you just may get a hub with a blue USB connector but running effectively at USB 2.0 speed. Test your hardware and sort out all that poor performing stuff.

There is another peripheral you can get surprises with - card readers for memory cards. Memory cards - the majority today are SD or miccro-SD cards - are used in lots of devices - cameras, camcorders, smartphones etc, and require now and then data transfer to a computer for further processing. The c't computer magazine testet USB 3.0 card readers about 3 years ago, at a time I got a Nikon D800/810 which uses fast Compact Flash cards.
the Transcend card reader - for CF, SD and other cards - Sony - was one of the fastet readers. I'm using a Sandisk CF card which gives me a 110/75MB/sec R/W performance with this card reader, and 88/74 MB/sec R/W with a micro-SD card. I have another older USB 2.0 CF card reader, it does not compete with 25MB/sec with this card.

I got some other (micro)SD card readers as an USB stick, the black one top left does about 60MB/sec, the bottom left one does 85/72MB/sec, and the blue one is a fake USB 3.0 card reader. It was advertised as an
USB 3.0 micro-SD USB card reader stick, the image was taken from the blank back side, this reader actually has a blue connector insert to indicate an USB 3.0 connection but the front side is marked with a print 'Micro SD USB 2.0', and the speed is USB 2.0 like with 26MB/sec. There is another card reader I don't want to forget, lots of notebooks come with a micro-SD card slot which runs at 70MB/sec R/W with this same card in my notebook, not too bad overall, but I tested such a card slot on another notebook as well which does just 40MB/sec R/W, so copying or using it for a backup almost doubles the time, but you cannot blame the memory card for this.

That's the fun part with Far East products - you never know what you get - not with such card readers - or USB hubs - or with SATA to USB converters. You really need to test everything, or you should not wonder why your SSD is so slow - when you run it with a slow converter on a slow hub if you are not careful.

The USB spec has been updated recently to USB 3.1 Gen 2 doubling the transmission speed to 10Gbps amongst some other additions and enhancements ; everything is compatible - supposed to be - backwards etc - until you plug it together and find out.............

This is about the smallest USB card reader for micro SD cards you can get


You find a similar UB 3.0 version here
https://www.ebay.de/itm/302676585338 (Ebay links may disappear after a while)
or as an USB 3.1 version with the small USB connector
https://www.ebay.de/itm/USB-3-1-Typ...181648?hash=item33f768f010:g:D3cAAOSw9E5byDkZ
I'm using some very similar plug to backup a notebook, Paragon backup/partitioning software let you easily create a bootable USB stick with their software in a WinPE environment. I do the backup of the system flash drive directly to the same microSD card with 200G, always after the Microsoft patch Tuesday and after a major new software installation . (My little card reader is running at full speed of the card, but you never know as shown above with other items.....)

May I add a funny detail about the notebook I'm using, a small 12" one which comes with 1 USB 3.0 connector on the right side, and an USB 3.0 connector and a USB 3.1 type C connector on the left side.
Both left USB connectors deliver about 450MB/sec transfer speed with a fast SSD, the connector on the right side creeps along with about 50MB/sec..................the hardware is full of surprises. That's def. enough speed for a wireless mouse, a scanner and other hardware like that but just not o.k. for major data transfers.

Time ago I exchanged my huge tower computer for a mini PC of 5x5”. Best move I’ve done in years. Quiet, unobtrusive, less electricity consumed, very little heat and no more fiddling with fans, liquid cooling and all that stuff.
Of course, those small devices have their inherent limitations ( i.e. no proper graphics card, but a combined CPU/GPU chip ). The number of available external connectors is also space constricted, Mine has 4 USB 3.0 ports and no USB 2.0. Funny thing is that the built-in SD card reader is USB 2.0. Shouldn’t have been easier and more logical to feed the card reader from the USB 3.0 bus instead of using a separated USB 2.0 bus solely for this purpose ?. Ask Asus ..

Ink stained Fingers said:

the connector on the right side creeps along with about 50MB/sec

Click to expand...

May be a USB 2 port. Just because the port is blue does not guarantee 3.0 - yes, builders have been known to misrepresent USB ports and their colors. Or something is throttling the bus speed such as one or both drives (if transferring data between the two), internal bus speeds, the USB port, the transfer cable if using an external drive, the bus speed of the external enclosure if present, the BIOS, etc

One way to determine potential throughput is to see what Windows reports in Device Manager as the theoretical max speed of the USB hub. From this link comes the following quote. It's a little dated - no USB 3.1 - but the principles still remain viable.

The short answer is there's no way, from an end-user POV, to conclusively test because you'd need visibility to the internal bus to measure the effective transfer rate. The suggestion to measure the actual throughput as seen from your terminal devices is the next best alternative.

However, you should check to see that your laptop (Windows device) actually classifies the USB 3.0 connection as a "super" data rate capable connection.

There are four USB specs: 1.0, 1.1, 2.0, and 3.0. But to confuse things, each USB spec has more than one data rate assigned to it. Those rates are "low", "full", "high", and "super."

Therefore, benchmarking data throughput solely on speed is not necessarily conclusive as to what the actual spec being used. Thus, a USB 3.0 port may not be actually running at a "super" rating but at a "High" rating instead.

On a Windows machine, check the data rating of the USB root/hub - Goto: Device Manager --> USB Controllers --> USB Root Hub (Right Click) --> Properties --> Advanced (Tab).

It should tell you the data rating for the USB hub/port. Once you know that, you'll know the maximum throughput from the computer's POV.

Low = 1.5 Mbps Full = 12 Mbps High = 480 Mbps Super = 5 Gbps

For other people reading this - then there's the actual transfer rate of the two devices (assuming point-to-point) that are communicating. For example, transferring something at USB 3.0/Super is going to be a tough between two endpoints comprised of 5400 RPM PATA drives.

Click to expand...

stratman said:

ust because the port is blue does not guarantee 3.0 - yes, builders have been known to misrepresent USB ports and their colors.

Click to expand...

I got it sorted out with the USBTreeView utility
https://www.majorgeeks.com/files/details/usb_device_tree_viewer.html
It actually tells you by far too many details about your USB connections, but I (un)plugged some devices on this and that USB-port to see where it comes up in the port listing, it's the 'H' and 'S' markings on the port numbers indicating the differences, and you find it in the Device Descriptor listing under keyword 'bdcUSB' .
https://superuser.com/questions/478184/verifying-usb-connection-speed-usb-3-or-usb-2
The product spec in my notebook user manual is wrong - it is listing 2xUSB 3.0 ports and 1xUSB 3.1 port, but there is one USB 2 port, with more internal use for the USB 2.0 connection for the Bluetooth transmitter and the camera .
The USB 3.0 connector is blue, the USB 2 connector is off blue, a muted blue-violett, the differences in color of the plastic inserts in the connectors are only visible under strong light , and you only see the differences in color if you know what to look for.

I wonder how the data in Device Manager compares with the findings in USBTreeView.

stratman said:

I wonder how the data in Device Manager compares with the findings in USBTreeView.

Click to expand...

I'm not getting much info from the device manager. Anyway - I got the types of USB connections on my notebook identified properly.

I just another USB 3.0 hub in - this one clocks along at 400MB/sec with an attached SanDisk SSD via an SATA/USB adapter which supports this speed as well. It's this one
https://www.aliexpress.com/item/32949218007.html?spm=a2g0s.9042311.0.0.3da24c4d2L4I47
(This product may become inavailable at any time)
Watch the display - you need to select an option - cable length and USB 2/3.0 - it's offering both, but you cannot connect an external power supply to it e.g. for 2.5" HDD's.
So yes - speedy USB 3 hardware is on the market if you can find it.