Samsung Galaxy Note 8 SMB and USB 3.1 file transfer speeds

I’ve written this page to inform you about slow USB and SMB file transfer speeds, and how to circumvent both issues. The most important thing to realise is that it is possible to overcome these issues; please do not let this page sway you from buying the Samsung Galaxy Note 8. In my opinion, it’s a great phone but no device is perfect.

Incredibly slow Windows file shares (SMB) with the Samsung Galaxy Note 8

When connecting to a windows computer i.e. mapping a file share via the use of SMB, the Samsung Galaxy Note 8 demonstrates incredibly slow file transfer speeds. After reading the community forums a bit, it seems this issue is present with previous devices. My theory is that this is some kind of power-saving feature. Interestingly you can speed up the file transfer speed if you download a file from a webpage and then download a file via SMB at the same time. I suspect this is the equivalent of running a game on a desktop computer to kick the processor into speeding up, and then opening another program at the same time. This method is pretty nasty to say the least, but it is useful to see what kinds of speeds the device supports. When you’ve only opened a file browser, speeds from about 600KB/sec to 1MB/sec are quite common, and this isn’t really acceptable, especially if you want to watch a movie saved on another computer.

The good news here is that there’s various ways to circumvent this issue. For downloading files, you will find FTP considerably faster. Windows server doesn’t support SFTP (it does support FTPS) as a native option but there are programs available which will let you install it. Moreover, you might not deem SFTP as necessary. For watching movies and whatnot, you might want to consider a program called “servio.” I do not let it do any transcoding, and I use it purely to pass the file; server CPU load does not seem to increase, but when the file is playing on the Samsung Galaxy Note 8, the bandwidth the phone uses is considerably superior (I’ve maxed out my Raspberry Pi’s WiFi speed for example) to using a Windows SMB file share method. You will have no problem streaming a bluray movie with this method.

It would be nice if Samsung gave the option to increase SMB share speeds; I know for certain the hardware supports it. If it was a setting in performance mode, it would please a lot of users.

My method basically boils down to me saying use the right tool for the job. If you want to transfer files, use FTP. If you want to stream movies, use a streaming program like servio. I am not saying this is acceptable, because other devices treat files in a superior way, but I am saying there is a pragmatical solution to the problem.

USB Type C USB 3.1 on the Samsung Galaxy Note 8



If you don’t want to read all of this, please read the bullet points:

  • I have achieved 70MB/sec+ speeds writing to the phone from a device connected to the USB port of the Samsung Galaxy Note 8
  • USB Speeds drop significantly, down to as low as 13MB/sec, when multiple devices are connected
  • The MicroSD card slot is fast and runs at USB 3.1 speeds
  • It’s quicker to copy files from an external SD card reader to the MicroSD card slot, and back again to a different SD card than it is to copy files from an SD card to a MicroSD card on the same USB card reader
  • If you’re looking for a portable backup solution to add to your professional camera, look no further but be aware of its USB limitations
  • You can load raw photographs quickly
  • You can edit raw photographs

Please don’t be too alarmed by what I’m about to say below. For the average user that has zero interest in plugging in multiple high speed USB devices, this will not affect them.

USB 3.1 isn’t always USB 3.1

The USB C USB 3.1 port isn’t always USB 3.1. I could be wrong, but it’s as if Samsung have implemented a crafty measure to slow the USB port as a means to lower current draw from the battery and therefore minimise heat (if you know about last year’s disaster, you probably know where I’m going with this theory…)

It’s not mentioned in the documentation anywhere and I am hugely interested in USB C USB 3.1 phones as I can use them as a portable backup device for my Sony a7rII camera (taking a laptop isn’t an option on long hikes.)

It’s not all doom and gloom though, take a look at this screenshot for example —

If you’re just plugging in the one USB device i.e. an SD card reader, and you copy files from that device to the onboard storage or the built in microSD card, you will receive full USB 3.1 speeds (my cards aren’t super quick, but I’ve gotten over 70MB/sec so I know it’s not using USB 2.0, for sure.)

Here’s the problem though… If you plug in a memory card reader with dual slots, with the intention to move files from a large SD card to a microSD card (NOT the built in microSD card reader) on the same USB reader, i.e. a hub of sorts, then it will revert to USB 2.0 speeds.

Some people have tested a few devices, noticed that a Samsung T5 SSD is fast and that their third party HUB is slow, and then drawn the conclusion that the Samsung Galaxy Note 8 (actually I think the comment I read was about the Samsung Galaxy s8+ but the same logic applies) favours Samsung’s own equipment. From what I can tell this is not true at all–non causa pro causa.

The limitation is based around the number of devices, not the brand of device. It could be entirely a software based limitation as the phone has the hardware to work in USB 3.1 mode; however, I’m not 100% sure. I suspect the port doesn’t supply the same amount of current as last years model.

There are a few ways to make a battery explode, 1) short it. 2) short it by crushing it. 3) discharge it incredibly fast. 4) charge it incredibly fast. 5) discharge it fast enough to expand and crush itself (if there’s not enough room in the case). 6) charge it fast enough to expand and crush itself (if there’s not enough room in the case).

The battery undoubtedly has more room in the case compared to last years model, and by limiting the amount of current to the USB port, it would be far less likely to discharge too quickly. In other words, I suspect they’ve gone safety mad. I’d be fine with that if they informed the user, but there’s no mention of this.

USB card reader information


USB card readers are mostly bad and most of them do not support sequential writes, but I have found a few decent ones.

When I connect my SD card reader to my computer, as a reference, the speeds slow up a bit and the card reader gets quite hot when writing from one card to another sequentially. With the Samsung Galaxy Note 8, the speeds can drop to as low as 13MB/sec after a lot of writing, (that’s 26MB/sec total USB throughput, as they’re both on the same port.)

There are two ways to think about this problem…

Above are two examples of how to transfer data. The last one shows data going from a large SD card to a MicroSD card on the same SD card reader. If you look at the screenshots below, the first one shows sustained sequential writing from an external SD card to an external MicroSD card. It’s not great.

The SD to phone photograph shows the kind of speeds I’ve achieved with the USB port i.e. 70MB/sec+ when only one device is connected. The SD to MicroSD picture is on the breaking point of maximum USB 2.0 speeds, but I suspect the limitation here is with the speed of the MicroSD card in the phone itself rather than it being limited to USB 2.0.

If you look at the MicroSD phone to SD speeds, this is faster than USB 2.0; in other words, I believe the MicroSD card slot in the Samsung Galaxy Note 8 phone supports USB 3.1 speeds, and a single device connected to the USB port also supports USB 3.1 speeds. Not only that, but when data is transferred from USB to the MicroSD card in the Samsung Galaxy Note 8 phone, the sustained writes do not seem to dip. They’re respectable, and remember, 70MB/sec writing is actually 140MB/sec total throughput.

My advice is to buy a 128GB MicroSD card. Use 64GB for phone storage, and 64GB as a buffer. Copy files from a 64GB SD card to the MicroSD card in the phone. Then plug in a different SD card or even a Samsung T5 SSD, and copy the files from the MicroSD card in the phone onto the second device.

You can leave the MicroSD card in the Samsung Galaxy Note 8 at all times; the only reason I suggest this method is because most phone cases suck more dick than a swedish pornstar and do not let you access the MicroSD card slot very well. If you have access to the MicroSD card slot with your phone case or you don’t mind removing your case frequently, then you might as well just put a fresh 64GB MicroSD into the Samsung Galaxy Note 8 phone and copy the files from an external USB card reader onto it.

This is a bit of a convoluted solution, but it is a solution nonetheless. I do not own a Samsung T5 SSD, so I cannot be certain what the speeds are; however, MicroSD in the phone to an SD card gives you 60MB/sec write rates, combine that with the first card at about 50-55MB/sec, and then half the value (as you’ll be copying to two separate places), and you could still be looking at 30MB/sec+ sustained write rates. Moreover, when raw photographs are on the MicroSD card in the phone, you can open them quickly. I would really like to get my hands on a Samsung T5 SSD as I’m curious as to how quickly you can edit photographs on that thing.

Remember, USB 2.0 is 60MB/sec maximum theoretical speed on one port (which you’d have to half if you’re copying from one device to another), so you’re still breaking USB 2.0 speeds in pragmatical terms, with this method and you get the choice of being able to copy to an SD card, MicroSD or an external SSD. With sequential writing on the same memory card reader, you’re pretty much limited to SD card to MicroSD.

Please read my Samsung Galaxy Note 8 review if you are interested in the phone.

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