I am currently in email conversation with Bitmain regarding the issues with the S2 (& soon to be released S3) & p2pool firmware/driver incompatibility issues. Bitmain have requested more info from me regarding the issues, however the type of info they require is a few levels above my paygrade/capability - so can someone either post here or PM me the exact problem & I will relay it to Bitmain.
This is an opportunity for the p2pool community to help increase the hardware availability for p2pool, something that so far has been severely lacking for the last year, and is especially important for the upcoming S3's - let's not miss out on this chance.
How can I help? I don't have any S1/S2 hardware to test with (if I did, P2Pool would probably work with it by now...) and haven't really gotten any concrete bug reports. I gather that they have high DoA rates, which I assume is due to high latency responding to pushed new work or high latency sending results.
The main things P2Pool needs in a miner are:
- Don't have arbitrary limits on the coinbase transaction size or the placement of the Stratum nonce within the coinbase (late generation Avalon miners are guilty of this).
- Send results/good nonces as soon as possible after they are discovered (ideally within 1 second).
- Start working on pushed new work as quickly as possible (ideally within 1 second). Also, don't drop good nonces if new work comes in (equivalent to cgminer's --submit-stales option)
If I am correct in assuming that the problem is latency, no simple solution will help existing devices. The parallel sharechains idea (which is my top priority) would alleviate this issue by moving away from the linear sharechain/30 seconds per share paradigm to one where latency matters far less.
Hey forrestv,
I wish I could give you details, but unfortunately I'm half a world away from my S2. What I can tell you is that when I point my S2 at my p2pool node (or any p2pool node for that matter) it will max out at 850-900GH/s. I point it to another pool and it hits 1TH/s without issue.
I'd ask that you contact mdude77 and kano. They have more details regarding what's going on with the S2.
By the way, the S1 works just fine with p2pool.