I actually didn't like Spondoolies that much. The SP10 was a 1U rack machine cooled by 1U fans which spun incredibly fast to move any air at all and therefore made pretty terrible noise. Their 2U equipment were still about three feet long, which meant by the time intake air got to the heatsinks at the back it was already oven-temperature and didn't cool effectively. Heatsinks were inadequate.

I started losing respect for Bitmain when they produced a new S7 model with a regulated string but firmware-locked the voltage. It had a lower parts cost than the first version (therefore higher profit margin) and significantly worse efficiency but they did their darndest to convince people it was better. The S7 is also when they went all-in on epoxied chipsinks, cheap and quick but unreliable and hard to maintain or repair. They also kept making their air paths longer and longer even as they doubled the amount of heat in the box, causing the same problems as Spondoolies. It took them too many years to figure out that was dumb.

Who I really like is those GekkoScience guys. Their schedule is pretty sloppy but the gear itself is decent 😁

Did you check the README for information on that error?

I am 100% in favor of using something called "Potato" to run Gekko miners. No idea if it works, but potatoes are great.

Voltage range is approximately 1.4 to 1.6; stock setting is 1.48

You musta bought from Merch, whose "brand" is strapping blinky lights on everything. Not sure anything with a fan swap would stop the string at 3 chips, so it's probably an actual flaw and repair/replace should be an option. Contact the seller.

It's less a theoretical max and more that that's about what users have reported. It's around 15 to 18, but depends on the speed you're trying to run.

That miner showing 3 chips is a hardware issue. Talk to the vendor.

I think the practical limit for a Pi is around 15 chips, so that'll run two R909 by itself. I don't know that anyone's gotten expected speed out of three together on one Pi.

Yeah the Pi runs these guys pretty well but it's entirely because of the OS scheduler that it's better than more powerful machines with OSX or MSX. Our production testers are old Dell 755 machines from approximately 2008 that are stable with 10xR909 at stock speed. Meanwhile, on a newer stronger Mac...

Unless there's been physical damage such that parts have been removed, the most likely issue is the chip - either the chip itself, or solder points underneath.

Power use increases with voltage, because the tiny switch gates basically act as capacitors so with a higher voltage, there's proportionally more current transferred to flip the switch on and off.
Power use increases with clock speed, because there are more switch flips happening.

As long as heat is managed, the only damage will be your hashrate tanking because the data no longer makes sense.

You're probably butting into the power headroom already. In fact I'm surprised you didn't hit it already, but keeping the main regulator cool probably helps a little with Rdson current measurement.

More voltage should give you more ability to clock higher, but the main regulator is current limited. Shouldn't hurt anything to turn the voltage up a bit and see where it goes. If you suddenly drop to no hashing and only fans drawing power, you've tripped the OC and need to power cycle the whole unit. The voltage range capable with the pot is safe; just make sure you keep the chips cool and there should be no damage.

I've got a test unit I want to mess with, raise the current limit (will require replacing some parts to raise the safety ceiling) and repeat some of your tests to see about improved cooling efficiency and push the hashrate super high.

Holy crap did you say 3.2TH? 725MHz should see 2.9TH but that's still pretty nuts. The main regulator should cap at around 120 watts output.

Your government probably has that program because heat pumps have an over-unity coefficient of performance - that is, they move more heat than corresponds to the wattage of electricity used - often by around 3 to 5 times. They're looking at net energy savings for heating versus directly burning gases or consuming electricity in resistive heat furnaces. A bitcoin miner is basically a resistive heat furnace and so is, rather than what they're trying to subsidize, more representative of what they're trying to replace.

Definitely check the heatsinks for tight screws. Reporting 5 chips is problematic; was it doing that from the start, or after running a bit?

Charles-Tim, it's not likely a scam it's guaranteed to be a scam. I run GekkoScience, have since we started in 2013, and I have no idea who's running the linked site. It is 100% a scam.

Indeed, pretty ridiculous. Their numbers though, I *wish* we could build a multi-TH stick miner. But yes, it's wholly fraudulent.

If you're looking for GekkoScience products, hit up the authorized resellers.

419Mining
BitcoinMerch
MineFarmBuy
AltairTech
Eyeboot sales via Amazon
bitshopper.de in Germany

Heatsink is about 45x70mm

Yes there's no interface between the bottom heatsink and the board. I'm gonna be doing some testing this week on a few potential changes to improve cooling, and underside paste is one of them.

So you did not buy directly from Gekko, therefore I request you amend your statement that Gekko took your money and ran, providing no service.

It's a bit troubling that Eyeboot, who did take your money and owes you service, didn't follow up properly. Try contacting him again, and tell him I sent you.

You would have to flex the case outward at the bottom a little bit to get around the board. If you unscrew the PCB standoffs from the base and slide the whole innards out the front, the case would come free without issue. There's a planned board revision for the next batch that addresses heatsink screws and also ease of [dis]assembly.