How does FoldingCoin differ from CureCoin which, AIUI, does the same folding@home calculations?
Both Foldingcoin and Curecoin do folding using Folding@Home. The difference is that Curecoin has its own blockchain which must be secured by mining the coins, expending extra energy. As I understand it, Curecoin uses both SHA256 mining (proof of work) as well as Proof of stake minting. So for Curecoin, people use CPU and GPU power for actually running folding@home, and there are also miners securing their blockchain expending energy.
You're mostly correct. There are some common misconception dating back to the launch of CureCoin about its efficiency. People also often confuse how CureCoin works with the way GridCoin Classic worked in the early days.
CureCoin is designed to split available coins roughly 80/20 between Folding@Home participants and SHA256 miners. However today, since difficulty is high, SHA256 mining activity is unprofitable in CureCoin and therefore very low. PoS takes up the slack for the low SHA256 participation. So as I understand it ,
today CureCoin uses ~90% of electricity directly on science - with the remaining 10% energy being split between SHA mining and PoS transactions.
If you fold for CureCoin, or merge-fold with FoldingCoin, you can allocate 100% of your CPU AND GPU power to folding - no SHA256 parallel mining is required (like it used to be in GridCoin Classic). But you still have the choice to use an ASIC in mining pools that support CureCoin. At this point, CureCoin requires very little SHA256 mining power to remain viable (but in 1.0 it remains an option).
If I'm wrong, hopefully one of the devs will correct me.