Ohhhh, ok. I think you're totally right for lowish volume runs like this. My information was in the context of where you have enough volume to amortize the mask cost out.
Maybe SiFive is eating the cost here either with the hope that they can sit at 28nm for a while and treat this chip as gravy train money in the long term? Or maybe they just want 28nm experience for higher volume runs in the future?
The problem is the lack of IO. If they had at least one SATA port and a PCIe port it would make sense to sell this long term. The only way they could possibly fix this problem is by connecting their chiplink to an external SATA and PCIe controller which means they need to fab another chip. This is going to be expensive so I don't see it happening.
