I am planning to buy a 27" 5k iMac but I was wondering... If I go with the BTO configuration and I get Fusion drive, I will get 1Tb 7200rpm Hard drive and an SSD in the PCIe slot, right? So what if I choose 256gb of SSD instead of? Will I get the SSD in the PCIe slot or will I get it in the 2.5 hard drive slot? Thanks in advance.