There is firmware that runs on the ARM CPU. If Apple ever sends an update for the SSD, it would be applied. The sintech adapter is only a pcie interface and can't be detected as a pcie device. The SSD is the pcie device.
Two of the 512gb ssd's in raid 0 would be faster than the new 1tb SSD. Since they are x2 devices, they would work on slots 3/4 in full capacity. I posted the numbers from a 512gb x2 earlier in the thread. If I would remember correctly, it would probably hit 1500-1600 mb/s as a software raid 0.
Thanks, that's what I was looking for. I couldn't run 2 of these in raid. My slots are all occupied. Looks like if I want 4X I'll have to get the 1TB.