Will this layout with a remote USB hub work?
My car is tiny (RX-7 FD) and I live in a not-so-friendly neighborhood. So two things I have to keep in mind when designing my CarPC are: compactness and security.
Therefore, I can't have anything visibly out in the open. Also, in terms of storage, I have a locked glove compartment which can just barely fit an EPIA mini-ITX board, and a locked storage bin (behind the passenger seat) that is about the size of a shoebox. Also, I have some space behind the touchscreen (installed in a double-din slot where my headunit used to be) to put the PSU and a fan.
The best way I could think of to fit everything was to use only USB devices for everything (including HDD storage) and run a single USB cable to the storage bin where I would put a 6-port hub and all my devices. So it would look like this:
(NOTE: I know there are a LOT of components missing from this diagram, like fuses, SDC, audio components, touchscreen, etc. I just wanted to focus on the USB hub related issues)
I know there will be a lot of current draw on the 5V rail due to all these USB devices and the USB hub. However, I will be using an Arise MPD-810H which provides up to 14A on the +5V rail. I think that should be plenty of juice, but please correct me if I'm wrong.
So, my biggest concerns are the following:
1) Is the 15' USB cable going to be too long?
2) My EPIA P4-ITX has a bios setting for booting off a USB-HDD, but can anyone confirm that this actually works? I will not have any IDE drives installed.
3) Will the 14A +5V rail provide enough power to drive everything in the rear storage bin (6-port USB Hub, plus 3.5" USB HDD, plus 4 USB devices)?
4) Will all of these devices sharing the same USB port hurt performance in any way?
5) Will need to use some sort of relay switch to completely cut power to the USB port when the computer is turned off? I heard that most new motherboards don't cut power to the +5VSB rail after power down. This would kill my battery.
Thanks for any advice.