Maximum size of flash drive/external HD that connects to an SP3 without using a Y-cable

[xbliss]

Size doesn't matter... 900mw is deciding factor. YMMV slightly.

Is that the USB 3 standard Max?

 

[hughlle]

Is that the USB 3 standard Max?

That's the usb 3.0 standard minimum. Many laptops etc offer a higher power output than 900mw, but the surface is stuck at the minimum power output for battery reasons (or at least I believe it is for battery reasons).

 

[GreyFox7]

That's the usb 3.0 standard minimum. Many laptops etc offer a higher power output than 900mw, but the surface is stuck at the minimum power output for battery reasons (or at least I believe it is for battery reasons).

No it's the USB 3.0 standard. Period.
For "Power" ports there are higher limits but vendors have implemented a hodgepodge of nonstandard ports as well.

Specification Current Voltage Power
USB 1.x and 2.0 500 mA 5 V 2.5 W
***USB 3.x 900 mA 5 V 4.5 W **** It's not a range, max or min.

USB Battery Charging (BC 1.2) 0.5–1.5 A 5 V 2.5–7.5 W
USB 2.0 with Type-C 500 mA 5 V 2.5 W
USB 3.1 with Type-C 900 mA 5 V 4.5 W

USB Type-C
1.5 A 5 V 7.5 W
3 A 5 V 15 W

USB Power Delivery
2 A 5 V 10 W
1.5 A 12 V 18 W
3 A 12 V 36 W
5 A 12 V 60 W
3 A 20 V 60 W
5 A 20 V 100 W

 

[xbliss]

Surface Pro 3 USB DVD/CD drives and getting them to work together

FYI

 

[sharpuser]

I have a 512 GB SDXC that goes everywhere with me.