I was speaking in general. The jessie installs have required more RAM in my own experience as well as this thread here: http://forums.debian.net/viewtopic.php?f=10&t=121214

Not saying the emulator or retropie has changed with anything, I am doing my first real Jessie setup of RetroPie right now as we speak (since the official RPi website has removed the old Wheezy image…)