the more ram you got, the better. I have it on one phone with only 512 MB of Ram, and CPU 2x1.3GHz. CPU is ok. XFCE with Iceweasel struggles with 2-3 tabs. So it is only useful for GUI-less tasks. The second phone I use it on - has Snapdragon 800 - 4x2.3GHz and 2GB RAM. Debian with XFCE flies on it.