As mentioned before, the limit is thermal derating of the main regulator. If you can keep that cold enough to not trip out, you can set the speed as high as you want.

Temperature is not available on USB. Nothing is. USB is wired straight to a UART adapter wired straight to the ASICs. If you can tag into the fan header (or the PWM testpad) it'll give you a rough idea of temperatures, within limits - it goes from 50% to 100% duty cycle between 30C and 60C.

The jumpers are a header used to program the onboard micro which handles string lockup resetting, overtemp shutdown and throttling fans based on heat. You won't need to know about it unless you are planning to write a custom firmware.

If you've got more questions, I'd try searching first. This thread and the dev thread can tell you pretty much everything, including the answers to all of today's questions so far.

I'm gonna bet most everything you need to know is in the first post.

Okay, but don't forget that the limiter is heat in the main regulator. Depending on heat, it could cut off at 15A or so, which is only about 6W per chip.

Also, that's a lot of finagling. I'd say once you're taking stuff apart it becomes "roast at your own risk".

You were lied to, or you seriously misunderstood. Who did you buy from?

These are tested at 200MHz, with a practical max of 275MHz. With 55 cores per ASIC and 8 ASICs per board, that's GH=0.44*MHz for 275MHz clocking in at a theoretical peak of 121GH.

Under pretty ideal cooling and power conditions, the BM1384 ASIC is good to around 500MHz which means the absolute best case liquid-cooled-miracle performance for this device could only be 220GH, still less than half what you want.

(in case you're wondering, I designed and built the R808 so I know more than "them")

I'm assuming 480GH is the desired aggregated speed from at least 4 units? That's about 275MHz, which is pushing pretty hard. Some people reported taller feet and under-board airflow helped increase stability. The actual limit on this board is thermal derating of the main regulator, which is the rectangular add-on board in the corner by the pot. Keeping that cool will also help.

Yes the fans on these are pretty crappy and I won't be using them again.

It looked like two fans back to back on each end, but it could be just one extra-super-duper fan. For the kind of cooling that would be infinitely easier to achieve from, say, an S4-sized housing. And also quite a bit less susceptible to dust. A lot of people don't consider just how much fan power draw, and chip-level temperatures, can hurt machine-level efficiency.

A longer housing for the same power would help with per-chip power dissipation, which in general means lower chip temperatures so easier cooling and longer expected lifetime. However, don't forget that the last chips in the line are being cooled by air that's already gone over everything ahead. This is a lot of why Spondoolies' 3.5KW 2U rack miners were impossible to run at rated speeds, and let's not forget the AM Prisma debacle. All things being equal, a short wide miner will always cool more effectively than a long narrow one.

MFB, if you're using a 135-chip S7, you can also undervolt for improved efficiency.

Yeah no, that's a pretty extreme fire hazard. If it requires 4 fans to keep cool, it should be in a box twice the size. Ask any mining datacenter in the world, they'll all tell you "keeping a miner from bursting into flames" matters quite a bit more than "being tiny".

Why are people so addicted to the S7 size/cooling concept that they'd try and shoehorn 2-3.5KW into what's already not a great plan for 1.5KW?

I actually haven't done much mining on my own in a few years. For about six months I was mining and reinvesting heavily and doing some mining-related work in exchange for miners, in part on somewhat of a dare, and turned a 10GH miner into around 2.5TH with no added cost by about April 2014. After that I shifted more toward picking up interesting hardware rather than pure profitability, and then I had to put everything I had into the business to stay floating for a while. The bulk of my actual mining the last few years has been for winter heat at home and in various spots around the shop.

I've been keeping a 100KW datacenter stocked, but it's all miners for about 18 other people. The electric cost here, when I'm at 100KW, is around 6.9 cents including all fees and taxes. I host for 8.9 cents, which means the "profit" from hosting exactly pays the rent when I'm at 100% capacity. That 6.9 cents is an aggregation of some flat monthly charges and a demand charge based on peak draw, plus a pretty low actual energy rate. I'm on a small-industrial rate scale in a rural co-op, so it's pretty decent, but the bills are still around $5k per month.

Had I my own miners instead, I could probably have been profiting handily this entire time. But to answer the actual question - no, I haven't shut down all mining because of unprofitability.

As for HaggsFinn, it reads to me as thick sarcasm.

In a self-moderated thread, can the moderator edit posts or just delete them?

Man, I friggin' hate futures trading and all that. I come from a century of farmers and that kind of BS has ruined the industry.

Especially not if coin keeps dropping about a hundred bucks a day. Been saving up my BTC for most of the last year for a new miner project and in the last 60 days enough value has evaporated to have paid for half the first batch. Most of what was set aside was taken in when BTC was approximately twice its current value. Been in the game for five years and I still can't get used to the volatility inspired by manipulation and speculation. Really wish more people weren't greedy or idiots.

Really not sure why that'd be necessary. Not like we're going through a lot of constriction.

No R808 in any condition is for sale.

Okay but at what power draw?

I mean, an S1 is also a few times more powerful than the best USB miners.

What's the expected specs on that guy?

Ah. I can't really help you there. I do all the hardware and firmware but someone else writes the driver. I could probably do it given enough time, but I'm already tied up with design and manufacturing and hosting and whatever else is going on at the shop.

VH integrates my GekkoScience stuff into cgminer. You might also talk to jstefanop (the MoonLander guy); I'm pretty sure he did both hardware and driver for his miners.

From what I understand, cgminer basically has the framework in it for pool communication and for organizing how work gets divided up and distributed. The particular format in which it is sent to the miner, and the particular format in which nonces are received, is hardware-dependent, as are any control signals (setting clocks, etc). The driver would mostly be a translator between cgminer's base structures and your miner's specific protocol implementation.

If you're already coding your own hashing function, why use someone else's protocol? There's no standard, and every manufacturer's is already different.
Also most of them aren't really published info.

Older Avalon (gen4 and back) datasheets can be found with some protocol info, but their stuff's a bit weird and changed a couple times in there. Bitmain's protocol has been relatively fixed from S1 to S9, and the BM1385 (S7) datasheet has decent info on it.

Honestly for used stuff, it really hasn't come up much. I'm mostly worried about folks who bulk buy with intent to resell and then don't support the customers they hand new stuff to. The whole point of prioritizing resellers instead of doing everything myself is because it offloads all of the customer service I currently don't have time for.

But if it's just one guy who bought a used stick off eBay, I'm probably not gonna sweat it that much.

Also I don't keep track of which serial numbers go to which people.

The 2Pac doesn't have a temp sensor. It runs until it breaks or until you turn it off.

Zero chips typically means either the voltage is too low or there's a hardware issue. If you've adjusted the voltage but it's still failing it's probably a hardware issue.
The last batch of chips we got for these were pretty unspectacular. We rejected a lot of them outright and I've been replacing a lot of them on the bench, but a lot of them were functional enough to pass initial tests only to crap out during a burn-in. I hate to think how many passed burn-in but are crapping out for customers. But that's why we got a warranty. I'd say talk to the seller, see if he might have some advice for testing, and might hook you up with a replacement if it proves to be defunct.

The chips would be running at about 1070MHz. If power draw was linear (no voltage changes, which seems unlikely) the chips would be pushing almost 10W each. That's not unheard of - S5 ran 10W per chip around 400MHz and people pushed them even farther with less effective heatsinking than the S9 has.

Of course, the S5 was also about one third the heat density of an S9.

The S5 also didn't have any kind of board-level regulator. 10W per chip is looking like over 60A through the main regulator, which already runs hot at around 40A. If the board is immersion-cooled, heat wouldn't be as much of a factor as the saturation current of the main inductor. Once that level is exceeded, at any temperature, voltage stability goes whackadoo and regulator efficiency drops off.