Linux 64bit, 4GB RAM, nVidia GTS 250
Short description of error
Cycles baking takes 3.6Gb RAM + 3.8Gb HDD(virtual) RAM for Normals. Then Blender crashes on my machine.
Blender Internal takes about 2.8Gb RAM and bakes Normals ok.
My machine has 4Gb of RAM. Also, normals take not so much time of calculation in Internal Blender.
Guys, possibly you can check Cycles and possibly find any memory issues?
Here is my Hi and low poly models with blend scene: https://dl.dropboxusercontent.com/u/26887202/blender/test_bake.blend
Here is small screen: http://i.imgur.com/Tn6tIiu.png
Exact steps for others to reproduce the error
Try to bake in Cycles and in Blender Internal.