Quote from: kano on April 05, 2015, 10:22:14 PM

Unfortunately that wont help him in any way (unless he was a big time miner)
/diff is relevant for fake (pseudo) shares when used by small miners
The p2pool share-chain diff is what you must meet before you get a share that will be paid.

The fake pseudo shares are controlled by +DIFF. The actual difficulty of shares you are trying to submit for credit (not just graphs/hashrate purposes) is /DIFF. Agreed that he's possibly too small for it to matter. (I have no idea what p2pool's share difficulty or bitcoin's difficulty are these days.) /DIFF is usually used by huge miners to reduce their shares/block by voluntarily targeting a very high difficulty target. Small miners running their own node don't need to worry about it, the vardiff logic won't push their target too high.

It's only a problem if you are a small fish in a large public node. In raw p2pool a year ago (no idea if the code has changed), the share-chain diff target for miners on a node was based on the node's hash rate (not the miner). Thus small miners on a public node also being used by other much larger miners would have diff targets higher than the share-chain minimum difficulty. By using /DIFF you can override that. If you want to make sure you always mine at the minimum possible share-chain difficulty, you could just use /1 since it'll make the share-chain difficulty the floor.

Relevant code includes my attempt to fold this into official tree:

https://github.com/forrestv/p2pool/pull/174

And iongchun's branch where he provides some config options to give you more manual control over how it works, but with the same intent/basic result. However, this only effects psuedo-shares.

https://github.com/iongchun/p2pool/tree/auto-worker-diff

Here is me trying to get iongchun's stuff merged in as well:

https://github.com/forrestv/p2pool/pull/187

TLDR: Public node operators should use both 174 and 187 to help small miners be served appropriate difficulty target automatically.