I believe I have identified the issue with sha256 miners on this pool.

My sha256 miners have been repeatedly crashing on this pool, obviously I don't want that but I like zpool so I'm hoping I can help fix this if need be   I've been dev'ing since the 80s so if I can lend a hand in that way, please let me know.

Forgive me for stinking at formatting, if there's something I can do to make what's coming more readable, again please let me know.
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This happens very consistently on both my Antminers and Spondoolies.

They're all running cgminer4.8.0 so the log output is nearly identical for all of them.

This would account for what some of the posts in this thread are saying about the slowly reducing hashrate reported by the zpool website that results in 0 hash.

What is the problem?

Well I would have to look at the zpool logs to identify the problem as this is expected behavior from cgminer but since that is unlikely I'll take a stab, it's likely:

When the algo switches coins, one or more of the coins is not sending proper (or empty, or headlerless) packets or NULLs to the miners, which the sha256 miners and cgminer read as empty/garbage, leading to the miner eventually dying. The pool software is not switching to a new coin at that point because it is not receiving the expected output from the miners either, leading it to attempt to resend the same packet over and over as the msg the miner is sending is telling the pool that it didn't receive the packet (hence the timeout), leading to an infinite loop or at least a failing one.


My suggestion:

Do a (relatively) quick look at the logs for the sha256 coins and see which ones have not created any blocks on this pool and remove them, or, trim the sha256 coins down to the only ones with a regular hashrate on the site. It's likely one of the non-producing coins that is causing the issue.

If there's anything I can do to help, please let me know- I love using zpool

have you tried using the stratum-proxie thing-a-majig that someone mentioned a little while ago?

Reckon they'll do like they've done a couple times before and reopen sales in a couple hours once we're all panicking and desperate?

Im not suffering as much as you guys with regards heat, but its been pretty warm here in the UK last week.

Right. I got two large van radiators off eBay. I got two Ford Transit ones.
I linked the two together with braded hose and sealed up all the connections using jubilee clips.
On the inside one I covered it with a box and left some round connectors on it, to suit flexible ducting that connects to the miners.

The outside one is mounted with a 230V fan to blow ambient air over it.
I then have a pump that pumps water through a copper tube with small holes, to spray water over the coil in front of the fan.
The discharge turns upwards and makes the water drip back down into a tray to re-pump over the coil.

I filled the radiators with water and used a central heating circulator to pump water between the outside and inside coil.
Gives a massive temp drop with the water spraying over the coil.

When the water heats up, dump it and charge the tank with fresh cold water.
In the UK im getting approx 15 Deg tap water.

Currently working on an Arduino with a temp sensor to monitor the water then dump when it gets warm.
Just a solenoid valve to dump with a simple ball cock to fill with cold water again.

Miners suck air from over the indoor coil which cools the incoming air significantly.
The adiabatic cooling to the outdoor coil really works.

Im hoping to build the thing properly in some stainless steel boxes and install it permanantly over the next few weeks.

Why not?

Sorry but it is the same... the miner failure?

 
??

Yes, you can see in the first picture the temp sensor is the little square guy in the center of the ring of ASICs.

I've also thought about doing a plate of aluminum across the back. The bottom layer has a few signal traces in it for the temp sensor, but otherwise is for the most part absolute ground plane - which means chips aren't belly-pad-sinked into it directly like on the S5, except on the bottommost node. This thing is designed for top cooling. I can change that layer around if necessary to give it a bit more heat flow into the rear face of the board without a lot of trouble, but then you have to make sure your heatsink is electrically isolated which tends to increase thermal resistance. That's a big reason most string boards are top-coolers - having 15 different voltage-potential planes all rubbing up against the same block of aluminum can get fairly risky.

If I retool for a different chip whose dimensions are any larger than the BM1384, I'll probably have to either go with fewer chips or give up on the CPU cooler. It was darn difficult to fit 8x 8x8mm ASICs in a 30x30mm space with room for routing. Any bigger would be impossible. But I could just build for a basic heatsink, maybe 80mm square with a case fan mounted, and make the chip field any size I wanted to fit underneath it. Of course I'd keep the same size and screw positions on future boards which could mount up to the same heatsink.

since Bitcoin is a Proof of Work coin, here's some proof of work.





Here you can see the new thing with 8 chips. I haven't debugged the buck yet so it's still running off the hacked '53 but that's okay. Shouldn't take long to work it out. Comm lines are run straight into my hacked S5 controller. I'm not sure what's up with this guy, if it's comm noise or what, but it doesn't get full speed. Ran overnight at 150MHz (should have seen 66GH) but only regsitered 52GH or so. Now it's set at 300MHz and I should see 132GH (or at the 80% metric set by the previous test, 106GH) but I'm only seeing about 87GH. It broke 100GH earlier but I think it's getting tired. Not sure what's up. But it's running. I have found one error on the board, I forgot to level-shift the chip reset coming out of the microcontroller, but it's hashing which tells me all the worrisome and complex parts are pretty much right. My level shifters are all good. Still need to test dividing PLL LDO voltage but I'll worry about that after the local buck is working.

Merry Christmas, chumps.

Nothing's actually spec'd for chip height, but the chip area is based on the Freezer7's footprint. I have standard 115x mounting holes and I have holes to mount the Freezer7 directly without requiring its plastic bracket. Any standard Intel cooler will probably have to be modified for height, which probably just means cutting some plastic or yanking out those clips and using screws.

Buying the cooler has always been only an option. "you can even leave the cooler off so people can use their own" is the default.