I'm quite sure that the operating voltage on SODIMM 144 pin memory module is +3.3V. I'm not sure if there has been +5V versions of this. Look out this link:
w w w. interfacebus. com/Memory_Modules_144Pin_SODIMM_PinOut.html
Sorry for broken link, but quests aren't allowed to post hyperlinks. :-(
-Petri-