External HDD self-powered vs USB-only power (no Y-cable)

[rs1n]

So I stumbled upon the following hidden Wii U menu option to turn off power-save mode on the external drive. In the copy/move/delete data settings, move the cursor down to the bottom of the screen. Then press down (on the d-pad) as well as start and select simultaneously and hold all three buttons. A power-save screen will then pop up, allowing one to enable/disable the USB power save feature.

My question is, could this be the reason that a drive will seemingly work and then suddenly stop working when it does not have its own power supply? That is, the Wii U puts its USB port into power saving mode and the drive stops working properly. With an external drive that has its own power supply, this should not be a problem. What got me to wonder about this was my attempt to copy my 250GB external HDD (A/C powered) to a 256GB USB flash drive. Only a few minutes into the copy process, I saw the black screen that shows up when you "unplug" a USB device (namely, external storage). I will try the copy process again and report back any findings. In the meantime, if someone has already tested external drives with power-save turned off, I would definitely appreciate some info so I do not end up wasting more time doing something that has already been done.

 

[godreborn]

No, that menu is for hdd going to sleep.

 

[rs1n]

Just providing an update of my observations. Apparently even USB flash drives do not get sufficient power even with the hidden power-saving mode turned off. While turning the power-saving mode off allowed the copy process to continue (copied near 200GB of data), once the flash drive was near capacity (yet still with plenty of space to copy what I was needing to copy), I kept running into the error message regarding the drive being removed improperly (which I did not do) or that it was not sufficiently powered. I am convinced that the power-saving mode is completely separate from the insufficient power issues at the USB ports.