[throwaway2048]

its unlikely google is going to release brands and model numbers, they considered the information "proprietary" in their previous harddrive studies.

[buryat]

With their scale they might be ordering custom SSDs.

Edit: yep, right in the paper: "The drives in our study are custom designed high performance solid state drives, which are based on commodity flash chips, but use a custom PCIe interface, firmware and driver."