"Each tor process consumes ~ 6 Mb of Ram. 6x8 = 48 ~ 64 Mb of RAM for Tor processes.
Privoxy eats about 2 Mb each. 2x8 = 16 ~ 32 Mb of RAM.
So, 128 Mb of RAM will be enough for Tor and Privoxy processes.
Squid-in will have memory footprint approx 128 Mb. We assume it eats 256 Mb.
Same for Squid-out. We got 768 Mb of RAM total required. If it is gonna be a real system - we assume 1 Gb hardware RAM
installed."