SSD Write Endurance 25nm Vs 34nm

[johnw]

But we don't know exactly how much parity data is being written so I won't (not sure it's a safe assumption that the full 8GiB of the sixth die is used for parity).

Right, we do not know. Intel calls it "XOR parity" which is fairly vague (obviously for single parity there is an XOR function, so XOR does not really add any info) and has reportedly described it as "RAID-4 like", but not exactly RAID-4, which makes sense because if it were exactly RAID-4, the parity flash would wear out much sooner than the other flash because RAID-4 parity has to be re-written every time any of the other flash chips are written. So Intel must be using some tricks to avoid wearing out the parity flash too quickly, so we cannot make any assumptions about how much parity data is written. Regardless, I suspect that the block-erases for the parity flash are not included in the SMART attributes.

As for how much flash is on-board 80GB and 120GB Intel 320 SSDs, I am not certain. I don't have any of those models, and I have been unable to find a circuit-board picture for those anywhere on the Internet. The ones I know for certain are 40GB/48GiB, 160GB/176GiB, 300GB/320GiB, 600GB/640GiB. I'd guess the 80GB and 120GB models have either 8GiB or 16GiB extra (one or two 8GiB packages).