File transfer speed with PC is too slow, why there is no USB Mass Storage option?

[admad]

Can you implement USB Mass Storage mode or point me to a way on how to transfer files to PC with a  speed that is worthy of 21st century?

On Z3 I had an USB mass storage option for file transfer between PC and SD card. Now it's gone, the only option for file transfer is an ultra bad MTP (Media Transfer Protocol) which is very slow! What's the point of having USB 3.0, ultra fast SD cards when a file transferring method is limiting all that to ancient times? I intentionally bought high speed SD card for my new phone (128GB, read 100MB/s write 90MB/s) but I'm limited to 6MB/s due to slow transfer protocol? Are you kidding me?! LTE speeds are higher than cable transfer, oh the irony is killing me...

I made a test, copying a 1732 MB file to a phone external SD card. Here are the results:
Sony Xperia XZ Premium (SD card: Samsung 128GB micro SD SDXC Class 10 EVO+ UHS-I U3 100MB/s Edition, write speed 90MB/s)
Transfer time: 4m53s (293s) which gives an average transfer speed of 5,9MB/s.

Sony Xperia Z3 (SD card: ADATA 32GB HC class 10, read speed 50MB/s, write speed 10MB/s)
Transfer time: 2m9s (129s) which gives an average transfer speed of 13,4MB/s.

Z3 clearly wins with much slower card... I didn't use my new card there because that would totally smash XZ Premium. Before I got my new phone I did however test Samsung card in my Z3, the writing speed was 30MB/s and it was limited by USB 2.0 on Z3. I was eager to see USB 3.1 on XZ Premium in action, but the result as you can see is tragic...

So please, tell me, how can I transfer files between my PC and SD card with a speed that is utilizing USB 3.x standard and high speed characteristics of SD card?

If MTP is the only way, why not implement USB Mass Storage mode, so that the device would really be Premium? Is 6MB/s all that this phone can do?

[Lord_viridis]

So, what cable you using?

[admad]

Cable is the one provided by Sony with XZ Premium.

I made some more test, looks like the transfer got higher on XZ. I've used same SD card this time.

12000MB file

XZ Premium: 22MB/s (9 minutes)

Z3: 29MB/s (6m49s)

I've tried the 1732 MB file again and got 19 MB/s on XZ Premium (90seconds).

Looks like XZ Premium is capable of around 20MB/s, there is still room for improvement. The 6MB/s in previous post must have been some anomaly (MTP is very bad so I guess anything could be causing it to slow down so much).

[admad]

I was pointed towards Taiwan website where they shown different speeds when using different cables. I've checked mine and it is Sony UCB20. Now everything becomes clear, Sony is issuing USB 2.0 cable for a phone that support USB 3.1... Congratulations :< .

So getting a USB 3.0 cable will probably solve the transfer speed problem, however it won't change the fact that MTP is simply tragic, I can't see some files on my SD card when connected to PC. I see them on android file manager I have on my phone, but they are not shown on PC in MTP mode... (These files where transfered on my Z3 in USB Mass Storage mode, that might be some clue).

[najodleglejszy]

my wild guess for the lack of Mass Storage is as follows: USB Mass Storage requires unmounting the SD card in phone and mounting it as external storage on PC. after being done with file transfer, the SD card has to be unmounted on PC (with "remove safely" option) and mounted on the phone. not only it makes the files on the SD card unavailable for the phone during the process, there's also a higher risk of corrupted data when the card isn't "removed safely" before unplugging the phone. I remember breaking my old Sony Ericsson cellphone's file system that way, and my Xperia mini pro not playing nicely with the Mass Storage option either (for example, apps moved to the SD card would be unavailable for a while after mounting the card back to the phone). I guess the slower copy speeds are the price you have to pay for the peace of mind that comes with being able to plug and unplug your phone without having to worry about data corruption.

[admad]

Yeah, USB Mass storage option has it's disadvantages, but why disable it at all? How about giving the user a choice, it could be even hidden in developer options.

MTP is seriously faulty, just look at that picture, I'm testing "Videos" folder on my SD card (sorry for the language, it's in Polish). Total commander on my phone shows 27.7GB in 7 files (4 folders), while my PC shows total of 15.8GB in 5 files (1 folder). This is totally unacceptable.

[najodleglejszy]

oh I don't mind Polish at all

after doing a quick Google search, it seems that Android in general has ditched USB Mass Storage in favour of MTP, so it's not just Sony thing. I've found this article that, apart from what I've already mentioned, lists some other reasons for why UMS is on Android no more.

[Thelastofus]

If you can't see your files when phone is connected to pc try this :

1)clear cache&data your file manager (for me it's "file commander")

2)restart your phone 

3) connect your phone to PC 

[admad]

I can understand why it was ditched, but why did they use MTP protocol instead of something better? It's 2017 and I can't see some of my files on SD card because they were copied to it using different device, it's just wow.

@Thelastofus

How can I clear cache&data?

[najodleglejszy]

probably because that's the best protocol they could come up with that was mostly reliable? who knows ¯\_(ツ)_/¯

I'm not sure if clearing cache in a file manager app will solve an issue with some files not being visible on your PC, but if you want to try it go to the phone's settings - apps - find your file manager app and tap it - storage - clear cache.