I have never heard of that. But, is it possible, probably. A Revo Drive is a desktop SSD that uses a PCIe port, but is actually 3 drives in Raid 0. So, while I have never heard of it, I would imagine if they can do that with a PCIe drive, it could be done with an SSD. But, I have never seen one for sale or advertised. I wish he had have given a link to some data on it.
That is unless he was talking about a hybrid hard drive similar to the Seagate momentus, which is a regular hard drive with a small SSD in it to boost the hard drive speed.