I don't know whether you'd need to do that to install a second PCI-E SSD. I'm not prepared to sit down with your manual and figure out whether competition for PCI-E resources would allow that with 28...

Whether you can add another PCI-E SSD depends on how many PCI-E lanes you're using, and the number your system supports.

Your I7-5820k supports 28 lanes. The I7-5930k and I7-5960X, 40 lanes. You...