I have a 27" late 2013 iMac with an apparently failing fusion drive. I understand that the drive is a 1TB SATA HDD and a 128GB PCIe SSD "blade." I have no idea which portion is failing, but disk performance is down the toilet, and at one point the Mac was reporting the drives were split. Oddly, they are back together now. Anyway, I want to replace the HDD with OWC's 2TB SSD kit. My question is what about the blade? Do I have to remove it? Can I remove it and not replace it? If I don't remove it, can I just ignore it? Obviously, leaving it and ignoring it is the easiest, and I'd prefer not to spend money to replace it, as I doubt it will help much with an SSD as primary drive even though the PCIE blade is faster than a SATA drive, plus I don't trust it anymore. thanks!