Got everything set up yesterday then discovered I'd left my mini-usb cable in a different city and that I was short one Cat6 cable. By then everything was closed to I had to wait until today to try things.
Anyway, I messed a bit with linux so I can't say what the vanilla memory and cpu usage were (ubuntu-NanoHAT-OLED version) but I know what they were before starting VH.
CPU avg load ~0.44%
Mem use 32/483MB
After starting VH as a daemon
CPU avg load ~0.50%
Mem use 34/483MB
So very little impact on the system with the daemon running but nothing connected. So I connected the camera and start live view then checked the usages. I saw nothing change on the OLED so I started htop which then changed the cpu usage on the OLED. Stopped and restarted htop and indeed, VH with live view running and connected to my desktop has no appreciable impact on CPU or memory use.
Live view uses the lowest resolution of the camera so I switching to imaging which is set to the highest resolution 4752x3168x24bit AND it downloads both a raw and an anti-aliased JPG of the same resolution (total about 25MB). Still, so no change on the OLED display and HTOP showed a 1/10th second blip of about 50% on one of the four CPUs.
I'm using Backyard EOS 3 and it seems completely happy. Backyard EOS 2, on the other hand, works fine on live view snaps but in imaging it complains that I need a cable to the camera. Live view is fine so obviously its an oddity with BEOS2 rather than a problem with VH.
This is going to be awesome! Now I can sit in my nice warm trailer all cozy while controlling my scope and taking pictures of galaxies and nebulae instead of freezing my buns off or getting eaten alive by mosquitoes and black flies!