Extremely Slow Data transfer to USB from Macbook M1 Pro

I just had the same problem. Tried to transfer a 2.7GB video file to a 32GB Sandisk thumb drive and it took several minutes to tell me it was going to take three hours. After checking on the internet and these support forums I tried reformatting the drive to an Apple File System which still took 15 minutes to transfer the file. Ultimately I transferred the file to my 2012 MacBook then reformatted the thumb drive to exFat then transferred the file back which only took 4 minutes. This is a huge problem.

It shouldn’t matter what hub or or drive you’re using, 3 hours for 2.7GB is pretty messed up. All I was trying to do was share a video with Windows users on a medium they can read. I should be able to buy a cheap hub and a cheap drive and be able to do that. My 2012 MacBook can do that but the M1 can’t. Outrageous!

FYI, you are reading the "Speed" information incorrectly. Both of the screenshots are showing 480Mb/s. The lowercase "b" is critical as it indicates "bits". An uppercase "B" indicates "Bytes". Both of these USB sticks shown in the last two screenshots are USB 2 which have a theoretical maximum speed of about 50MB/s.

If you want a fast USB stick, then you will be paying a lot more to have one capable of just 320MB/s write speeds such as this SanDisk USB-A stick (I couldn't find a USB-C Sandisk with that write speed, but I only performed a quick search). Most of the other SanDisk USB sticks have much slower writes closer to 130MB/s.

https://www.westerndigital.com/products/usb-flash-drives/sandisk-extreme-pro-usb-3-2#SDCZ880-128G-G46

FYI, I would not use a USB stick for any critical data as many USB sticks are of really poor quality. When I test them, many USB sticks (even name brand ones) tend to have random intermittent bit flips which corrupt data. I definitely would never store my only copy of any data on a USB stick. As far as quality, the SanDisk USB sticks are definitely one of the better more reliable brands.

Edit: You also cannot use Activity Monitor to monitor speeds of external drives.

Jbrown75nr wrote:

I just had the same problem. Tried to transfer a 2.7GB video file to a 32GB Sandisk thumb drive and it took several minutes to tell me it was going to take three hours. After checking on the internet and these support forums I tried reformatting the drive to an Apple File System which still took 15 minutes to transfer the file. Ultimately I transferred the file to my 2012 MacBook then reformatted the thumb drive to exFat then transferred the file back which only took 4 minutes. This is a huge problem.

Did you even read my earlier posts in this very thread to the OP regarding the issues with various USB sticks especially regarding the maximum speed of various USB sticks? Have you tried the Sandisk USB stick I linked earlier for the OP which is the fastest USB stick model available? You provided no details to assist you such as the exact make & model of the Sandisk USB stick used so we can verify the maximum speed of your USB stick.

It shouldn’t matter what hub or or drive you’re using, 3 hours for 2.7GB is pretty messed up.

Not all devices are compatible with all computers. Plus hubs, docks, and adapters/dongles can add to compatibility issues. See the end of my post for more about compatibility issues.

All I was trying to do was share a video with Windows users on a medium they can read. I should be able to buy a cheap hub and a cheap drive and be able to do that.

Notice what I highlighted....cheap. You do get what you pay for especially with electronics. While a Sandisk USB stick is one of the better more reliable brands out there, Sandisk has many different models of USB stick. The majority of them are slow (even if labeled as USB3...just means it is compatible with USB3, not that it is anywhere close to maximum USB3 speeds), but Sandisk does make a few USB stick models which are very fast, however, you must pay up for that speed...cheap won't cut it. See the link I provided to the OP earlier in this thread, plus my other responses to the OP regarding USB sticks and performance and reliability.

My 2012 MacBook can do that but the M1 can’t. Outrageous!

Not all devices are compatible with an M1/M2 Apple Silicon Mac, especially older devices. I have personally encountered this issue. There was also a thread on these forums regarding issues with some Samsung USB SSDs...where I believe it was some T5 SSDs worked, but others did not. An inquisitive user discovered the two seemingly identical SSDs were from different generations and used different USB chipsets in their drives where one worked and the other did not work.

Plus there have been multiple posts on these forums regarding drive issues when certain other devices are connected to a Mac (Intel or Apple Silicon)...most notably when a Wacom tablet is also connected.

So there are a lot of reasons and ways to encounter issues and this doesn't even cover possible third party software which may be interfering with the normal operation of macOS.

vijeth21 wrote:

All,

I am using Portronics usb-c to usb 3.0 cable to transfer my data from macbook pro M1 to usb and my data size is just under 2GB and still M1 takes about 2 hrs to copy files. The manufacturer has specified data transfer rate up to 5GB/Sec on usb 3.0 port but macbook is not delivering the expected performance any advise please?

This is really bothering as my windows laptop is able to do the same task in few minutes.

2 GB...(?) 2 hrs...

Is this a one off issue or for every external USBC to USB connection?

Did you try a different external to compare your results?

It would seem to be some corruption on the external device/incompatibility?

How is this external device formatted?

Is there 3rd party translation software involved?

Connect and use other storage devices with Mac

Erase and reformat a storage device in Disk Utility on Mac

Erase and reformat a storage device in Disk Utility on Mac - Apple Support

vijeth21 wrote:

I am using Portronics usb-c to usb 3.0 cable to transfer my data from macbook pro M1 to usb and my data size is just under 2GB and still M1 takes about 2 hrs to copy files.

What USB drive or device are you transfer the data to? A USB hard drive will only have a transfer rate of between 70MB/s to 150MB/s at best. Many USB sticks (aka "thumb drives") will only transfer data at USB2 speeds which are about 50MB/s. Even some USB SSDs may be just as slow as some hard drive depending on the exact model.

Plus not all adapters or external devices are compatible with an M1/M2 Apple Silicon Mac (usually devices which utilize older chipsets in their USB/Thunderbolt controllers). In addition other devices connected to the computer may interfere with the transfer to a USB device, so make sure to disconnect all other external devices to make sure one of them is not causing a problem.

Also try performing the transfer while booted into Safe Mode which will prevent third party software from launching automatically during boot & login. If Safe Mode works, then the usual software culprits affecting performance are anti-virus apps, cleaning/optimizer apps, and third party security software....none of which is needed on a Mac. Uninstall these apps by following the developer's instructions.

vijeth21 wrote:

I tried with multiple externals, all are working on same speed( 2hrs for 2gb of data) as per the usb- c to usb 3.0 converter manufacturer it supports up-to speed of 5gb per sec transfer rate.

I highlighted, italicized, and underlined the most important part of your post....The adapter supports speeds up to 5Gb/s, but it will depend on the actual device/drive connected to the adapter/converter on whether those speeds can be reached. Please look at my earlier post where I gave very specific examples of the maximum transfer rates of many USB sticks (aka "thumb drives") and hard drives. While most USB 3 SSDs should be able to achieve 5Gb/s (or a max of 600MB/s), not all SSDs will write that fast since write speeds of an SSD depend on the size of the write cache of the SSD.

What is the exact make & model of the SanDisk USB stick you are using for this data transfer (provide a link if possible since some of them can be very hard to tell apart)? While some SanDisk USB sticks can write at 400MB/s, many of them will only write at much slower speeds even if the USB stick itself says it is USB3 compatible. "Compatible" does not mean the device can work at the maximum speed of the protocol. I know this can be a bit confusing...some aspects of the USB3 specifications can be very confusing even to techs (even I have to look up things in the USB spec to confirm speeds & features all the time).

One of the issue i am suspecting here is my mac hard drive is 95% full, do you think it makes any difference during data transfer?

Perhaps, but see above.

<< my mac hard drive is 95% full >>

It's a wonder your MacBook Pro has not already crashed in a very spectacular way.