SMP with iMac 27" (2013/14)

I'm a sysadmin for a University, and I was setting up a new iMac 27" triple booting Mac OS, Windows 8.1, and Ubuntu 14.04 x64. I have all of the operating systems working and booting procedures fine, but am unable to boot Ubuntu properly unless I append nosmp as a kernel parameter at boot. I did a bit of research, and it has to do with Symmetric multiprocessing. Ordinarily I would just leave it out, but with SMP turned off, only one core shows up for use. Obviously for someone who wants to utilize the full power of their machine, this won't work.

tl;dr Ubuntu won't boot unless nosmp is appended to kernel. Need to figure out a way to have SMP turned back on so that all processors and cores can be used.

Thanks so much!