It seems like they have managed to fit 32 1P servers in a 42U rack. That's pretty impressive, I have to admit. I don't think I've seen that level of density before.
Also, I remember for example HP BladeCenter BL20p systems. There you would have up to 8 or 16 servers per 6 rack units IIRC. So about 56 to 112 servers in 42U.