I use to use my rpi3 which had retropie install on it also as a plex server and had torrent software on it, I used it like that for around 8 months and everything was fine but the only problem I had is I use to take the pi to friends houses alot at weekends then the kids use to moan that they couldn’t watch anything on plex whilst I was out lol.
But it seems retropie uses less resources when idle than magic mirror does.
For example if I enter “top” on my magic mirror electron is running twice and cpu usage is around 25-30%.
Retropie on the other hand idles around 1-3% only even going up a couple of percent whilst streaming to my smart tv.
I think I’ll just have to pull out one of my spare memory cards and see what happens I think.
For sure I’ll post back my results here just for everyone else’s information:)
Cheers

Taking this topic back to the storage question above, I did a fresh install on another rPi-3 and captured some info. One a stock Raspbian Jessie, running on an 8G card, with all apps updated, nothing removed, once you have MM up and running, you’re looking at the following for storage:

0_1462937551153_stock-raspbian.png

Now, since you’re likely to only use this for MM and nothing else, there’s no sense in leaving all of the other apps on it that are pre-installed. So, I removed some of the big ones:

wolfram-engine scratch nu-scratch sonic-pi idle3 smartsim penguinspuzzle java-common minecraft-pi python-minecraftpi python3-minecraftpi libreoffice*

And after running autoremove as well, which cleared even more space removing other unneeded apps, you’re down to this:

0_1462937986891_slimmed-raspbian.png

That’s 1.3G worth of storage that I just cleared up. So unless you need a larger SD card for other stuff, an 8G works just fine. Potentially even a 4G. You’ll still have plenty of room left after you clean up the installation.

Another option is to start with Raspbian Jessie-lite on a 4G card, but then you have to install the X server, desktop environment, and a login manager yourself. Assuming you get it all done correctly, you’ll end up with a very light weight installation of the OS, taking up only 53% of storage (remember, 4G card), with MM running lean and clean on top of that. I did try that as well but ran into issues with electron.js and for the time involved, knowing I wasn’t going to run it on there, it wasn’t worth continuing. I will leave that as an exercise to the brave.

OHHHHHHHHHH… yep I get it now thank you so much for the help and for the speedy response your mirror creation is the best.

To update electron enter your MagicMirror folder any execute npm install :)