Hello, does anyone know why when I attempt to copy a file (6 GB) from my HDD to a USB thumb drive, does the transfer rate start off at 77 MB/s and then quickly slows down to less than 10 MB/s and then crawls along to the point where it takes forever to complete and essentially stops at 67%? I tried the transfer a second time where I rebooted my PC and even reformatted the USB thumb drive to see if that would help, but it didn't seem to make a difference

I am using Mint Linux on a Lenovo T430 Thinkpad.

Thanks in advance!

My IBM T430 has always moved slower transferring files from the internal spinning hard drive to usb flash drive. From usb to internal drive however. It is faster.

Mine never stops at 67%. But then. I just walk away and give it time to finish. I don't run Mint/Ubuntu on mine. With all it's processes running while I do things. I run rox file manager or spacefm with a window manager on mine . Uses less resources.

http://www.binarytides.com/linux-test-drive-speed/

Do you get the same behavior with a different USB drive? Preferably a known good, fast one.

Thanks so much for the link on testing read/write speed of usb and ssd drives. Here are my results:

Kingston USB (approximately 4 or 5 years old)

READ speed
dd if=/dev/zero of=./largefile bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 186.877 s, 5.7 MB/s

Write speed
dd if=./largefile of=/dev/null bs=4k
262144+0 records in
262144+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 48.3306 s, 22.2 MB/s


Walmart USB (recently purchased)

READ speed
dd if=/dev/zero of=./largefile bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 168.204 s, 6.4 MB/s

Write speed
dd if=./largefile of=/dev/null bs=4k
262144+0 records in
262144+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 30.4706 s, 35.2 MB/s

When I tested with the Kingston USB thumb drive, I get a similar result - meaning after about 1GB of transferred data, it immediately starts to slow down at stops at 67%.

Is there a way to list or determine the types and number (and maybe speed) of USB ports on my PC with a specific Linux command? This might help me determine if there are any USB 3.0 ports, etc. Also, could this have anything to do with the type of formatting (FAT, FAT32, NTFS)?

Formatting the thumb drive as Ext4 fixed the problem and the file eventually transferred.

Yes, FAT32 has a max file size of 2 or 4 GB, I forget which.

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Unfortunately, "thumb drives" are built using RAM technology that is designed to support very large data-capacities with minimal power consumption. These technologies are designed to favor reading, but they do so at the expense of writing. It can be very(!) slow for any sort of computer to write to some "thumb drives." The type of filesystem that you elect to use really doesn't have anything to do with it.

That's the key: 4 GB is the 67% of 6 GB.

Concerning the write speed, cheaper drives are slow or very slow. More expansive ones can be faster.

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Update... Yes, the file did transfer from my Linux PC to the USB thumb drive after formatting it to Ext4. However, the problem was that Windows 7 would not read the thumb drive. After reformatting the thumb drive as exFAT (using the "mkfs.exfat -n" command), both my Linux and Windows PCs can recognize the thumb drive. Thanks for everyone's help.

Just as a follow-up, even though your T430 will only have USB 2.0 ports, you might like to try the SanDisk 'nano'-sized Ultra 'Fit' USB 3.0 drives. I know it sounds crazy, but they still read/write thru a USB 2.0 port considerably faster than a standard USB 2.0 drive will.

Read/write times/speeds vary considerably from one manufacturer to another, and also from one device to another within the same range. There's even noticeable differences between identical models.....

On the whole, you can say that USB 3.0 drives will transfer faster, regardless of the type of port they're plugged into.


Mike.

The T430 has 2 USB 3.0 ports

OP - they're the blue ones

It sounds crazy but it's technically very sound. As has been previously said, most [USB 2] drives are built with cheaper slow components. USB 3 drives are built to perform faster than USB 2, as users expect them to be faster, and these components allow the drive to run at, or very close to, the full USB 2 spec.

Fun fact... a 1Gbit USB 3 ethernet adaptor in a Raspberry Pi can sometimes perform faster than the onboard ethernet connector as the onboard ethernet is ultimately driven by USB 2 and the above comment applies.

Thank you

It's almost certainly due to Linux disk caching.

I've noticed a similar effect (on a lesser scale) when copying a large file (8GB+) from one hard disk to another identical one.
That's assuming the Mint progress bar can be trusted.

I confirm that USB3.0 drives work significantly faster than USB2.0 ones even on USB2.0 ports.

Otherwise, I found some years ago a FAQ in the "USB Consortium" 's web page, where developers were encouraged to cut the bitrate to a value, say 30% of the full bandwidth, in order to leave bandwidth for other devices to work on the USB bus. I effectively remarked that the highest transfer speed (to external USB-connected hard drives) was near the 1/3 of the full USB 2.0 bandwidth of 480 Mbit/s.
I wouldn't be surprised if some manufacturers would use higher allowed speeds in their more expansive devices