On 4/19/19 7:49 PM, Paul wrote:
philo wrote:
I have not posted here in ages as all has been going very well. Now I
finally have a question.


I have an Android phone LG-6 that I back up to my main computer on
occasion. The file copy is extremely slow and just yesterday noticed
the operation stops or does not take place at all on nested folders
just two or three deep.

I have tried both USB-2 and USB-3 ports with the results.


The machine dual boots Win10 and Ubuntu 18.04 and has the same problem
with both operating systems , so I know it's the hardware.

The problem is only evident when I try to backup my phone, no problem
with an external HD.


Since I have five machines in my house that are used frequently I
tried them all and the file copy works fine on two of the machines.


One of them is the newest machine in the house (win10) and the other
one, the oldest (win7).

I'm a bit stumped. Any ideas?

The protocol used is probably MTP.

Regular USB storage devices use the Mass Storage protocol.

MTP is supposed to be a file-by-file kind of protocol,
but Google made some additions to the protocol which
allow sending pieces of the file at a time (big pieces).
No transfer is segmented a sector at a time.

You can use USBTreeView and verify whether the device
negotiates USB1.1, USB2 or USB3 rates. The PHY rate
would be independent of the lazy ways of MTP protocol.
A separate factor in terms of potential issues.

https://www.uwe-sieber.de/usbtreeview_e.html

** Paul




Thanks Paul. Gives me something to check.

At least now I know which machines are best for me to use for backup