Are there any photos or layouts of the upgrade kits for the S1/S2, is it true the S2 could be upgraded to do 2Th/s?
That's the theory right now, but nothing has been released, AFAIK, other than the drawing in the OP.
I don't think S2 upgrades are that high on their priority list tbh, will be a month or two before they bother offering upgrades for them, simply doesn't make sense to upgrade the S2s yet.
S2 will be profitable to mine in the next two months, and it will be perfect time to upgrade then.
Upgrade in two months must be really cheap to have sense (but i'm still thinking that if bitmain will give it for free but will charge a DHL shipping, the upgrade will be worthless)
hope these will be true in the mean time
in my place, electricity always down once a day for 2-4hours
so it'll be really such a pain in the ass cant mining full 24h