USB3 Drive Base Disconnecting During Write Cycle

I am having the same problem:

WD My Passport Ultra 3TB, USB 3 interface (2 drives were tested, both brand new)

• read operation seems to be OK (didn't do a thorough test, didn't stall)
• write operation stalled after 5-10 seconds, always

My Passport (older generation 2TB, USB 3 interface)

• read OK (intermittent lock up while playing games from this drive)
• write OK (seems to be OK)

All three drives work fine with my older Surface Pro 1

Tentative conclusion:

This is definitely a Surface Book USB Port issue. Hopefully, it's fixable with a driver update. 

P.S. I am on lot#1544 (i7 256 8GB), not on insider build.

To continue my saga here I went home to try something out.

I took an old 500gb Seagate 7200rpm 2.5" laptop HD that used to belong in my old Macbook Pro, and stuck it into my StarTech enclosure. I ran Crystal Disk Mark and it tested out fine. No drops.

I also tested out my Western Digital MyPassport 2TB HD, and that also worked fine.

So, for my Surface Book with the latest updates (including the latest hardware update) installed and a later Lot # of 1547, my problem is now isolated to 2.5" SSD's in an external enclosure.

I'm also using a T1 and I am having the issue. I've also tried powering the T1 externally with a splitter cable so and sadly that didn't appear to help in the slightest

For me, the exact same thing happened with SSD or 2TB My Passport, directly on port or connected to a Targus dock (powered). So, I don't think it has anything to do with power.

As I have mentioned before, it also can corrupt some of the files it does transfer before it disconnects. This is a serious issue.

It took me a while to get a new Surface Book after returning the original one.

The new one is a new LOT #, 1547, and sadly, the same issue with my StarTech SSD enclosure.

I did pick up a Samsung T1 500GB External SSD, and that works fine... So, my only conclusions is there must be something not quite right in the USB ports. I tried 2 different brands of external USB3 enclosures and 2 different SSD's. Both dismount during heavy write cycles. These same enclosures and drives work fine on my desktop, Surface Pro 3, Macbook Pro, and Asus Gaming laptop. It's just the Surface Book, can't seem to handle an enclosure that uses a normal laptop SSD. 

So, here's a summary of my issue if anyone at MS wants to look into this:

1. External USB3 Enclosure with either a Samsung EVO 850 500gb SSD or Crucial M4 500GB SSD will unmount during heavy write cycles.
2. I've tried having only the enclosure attached.
3. I'm testing running Crystal Disk Manager to test the read/write speeds of the drives in the enclosures.
4. I tried 2 StarTech enclosures and an Orico enclosure. All 3 dropped during the first write cycle, Read is always ok.
5. I tried a Samsung T1 500gb External SSD, and had NO issues.
6. All 3 enclosures worked fine on my Surface Pro 3, Mid 2014 Retina Macbook Pro, Asus ROG Gaming laptop, and a custom built desktop with an Asus motherboard.
7. The drives worked fine when I used my Inateck external drive Dock, which has it's own power source.

Lastly, I installed every update Windows Update found today.

Everything seems to point to the inability of the Surface Book to handle the power draw of a laptop SSD in an enclosure.

If anyone else has any suggestions, I'm open to them...

Dower