I just this evening lit up a dual-chip board - with two chips in parallel, not strung. It's definitely pulling the amount of power I'd expect for two chips actually hashing, but cgminer's only reporting single-chip speeds. Might be a comms issue with the second chip. The good news is I'm getting a lot better at sticking those things down. I'll play with it more tomorrow. Right now it's about time for me to take care of some other work so I can go home and get lunch before 10PM. Mondays are usually fairly administrative so we blew a lot of time earlier today talking about budgets and tool purchases and annoying people and stuff.

No pictures yet. Maybe tomorrow.


Okay, so the problem was pretty obvious when I actually looked for it. Com lines to the second chip were solder bridged. Apparently now it's cooking; I have 150MHz about 17GH reporting. It should settle out to 16.5GH overnight. If it keeps working well, tomorrow I'll rig one up with a second chip in series and see if it does anything better. If it works, I'll design the Amita PCB in parallel with the Compac retool and try to get prototypes of both at the same time. Hopefully that's in the works by the end of this week.

I'm actually considering buying one, just to see what it'll do and actually know things for real. I like knowledge. I don't like assumption. I've never though of myself as holier than anyone else here, just more vocally annoyed about people who are very vocally annoyed about the same thing over and over without actually doing anything about it except increase the general "useless noise" level in almost literally every thread ever. Do I agree with everything Dogie says? Nope. But do I agree with taking everything Dogie (or anyone else) says to the extreme and threatening legal action over every available comment, and commenting the same opinion I've already expressed repeatedly based on no experience with the thing being discussed, as a thinly-veiled means of staying "on topic" while giving myself another opportunity to be a dick to someone I've never met? Additionally, nope.

I'll just leave this thread alone until someone puts up a review about the actual product. Might be me. Who knows. Y'all have fun with it.

And I can't believe people haven't yet gotten tired of flaming Dogie in every thread on the forum. Does anyone want to fetch one of these PSUs and formulate an opinion based on actual performance and inspection, or do we want to just keep trash talking anything and everything based on a few scattered bits of information and massive doses of prejudice coupled with the comfort of relative anonymity?

Seriously, guys. The only way you can say something that hasn't already been said a hundred times is to actually discuss the product for which this thread exists.

They're about 1W/GH device-level. So not great, but not terrible for playing with. They're also pretty quiet.

As soon as people stop asking that question.

I've got about seven of those R-Boxes on the shelf and a few more that need fixing. They're nice little machines.

My first choice would be on a mountain in Wyoming, but I was just this evening discussing Alaska with some folks.

Also, I definitely did no real work this weekend. I mean I finally fixed the windows in my Jeep, but I didn't really work on miners at all. Tomorrow I may do some more testing on noise limits or something on the Compac, and work on the L-board for two-chip base Amita testing. Or I might just sit around and talk about awesome stuff with Novak all day. Who knows.

I've got three stickminers running right now, but one's a BlockErupter still plugged in from TheRealSteve's contests and the other two are prototypes.

I know a guy that found a block with a USB BE but that was over a year ago. He was bench testing it and the thing had only been running for about half an hour.

If I leave Missouri it better be for somewhere colder. Somewhere with a peak summertime temperature of 15C or less would be great.

"The burgers and tshirts have spoken." I'm not sure I've ever felt like more of a midwestern American than I do right now.

What if... what if we made a burger... on a t-shirt?

The stock boards don't have the current measurement anymore; that feature was too expensive to implement in mass (not many people wanted it). Also, the Bitmain PSU is C13/C14 plug and the DPS2K is C19/C20.

The best I could find was the stats on the DPS2500.

When you say "extra large" what do you mean? The wire is always 16AWG but I can vary the length.

Also, initial tests with the new inductor are less responsive than the barely-functional standard inductor from yesterday. Not sure why yet.

That's actually the primary reason we're out of pocket on this project, because I'm saving my organs for a special occasion and I'd rather not mortgage them away for a stick miner.

Though tell you what, anyone wants to support the business in a more direct way, feel free to buy power supplies. I don't know what hardware is still shipping what folks need supplies for, but we have a few 750W and 2000W still around and another batch of 750W board parts inbound. I've been focusing on this miner a lot lately and haven't really tried to drum up any sales, but we really like sales since that sorta also pays the bills. And then there's the 12KW of hosting space we have open right now. That doesn't really pay the bills but it is self-sustaining.

Production costs should be relatively unchanged - it'd just mean another pass on the pick-and-place and another bake, with a different thermal profile and a different solder paste with a different melting point... yeah, it'd suck.

I've already lost two weeks to the previous regulator design, and one week to figuring out what's going wrong with this board. Though admittedly I did kinda waste a few of those days not being terribly productive.

The breakout boards will probably allow me to skip some official revisions. I'm hoping the Amita will be pretty much a hole in one, if I can iron out the main details on the new multi-chip breakout and build it as an extension of the Compac with the same power and comms.

So, general testing update.

I was worried about comms - I've never been fully satisfied with the UART level shifter I had on there. And based on I think on vs3's comment that USB lines could be finicky, I was a bit skeptical about comms. So I peeled off the CP2102 on a stick I had working moderately, and ran it off the Novak USB adapter because that had proven itself on the breakout boards. Same performance. Rigging up a diode-drop level shifter for the RX line (to bypass the actual level shifter chip) gave me a bit better logic level hysteresis (and I might end up using it on the final since it's simpler, cheaper and more resilient than the level shifter chip) but the same overall performance. So then I says, well what if it's regulator noise hosing up the chip? I was seeing about 200mA draw being pulled by the whole hub and occasionally around 400Mh reported speed with sporadic shares reported, so obviously something wasn't right - I should have seen 600mA draw at least at the numbers I was running. But the breakout board, with identical circuitry, worked just fine - except its regulator was more distant than and also orthogonal to the ASIC, which was itself under a large aluminum heatsink.

So I yanked an inductor on a moderately-functional board, wired up some pins to drive it off my test schfifty-three board (the one rigged up for the dual-chip testing with the original breakout boards) an inch or two away (on the other side of a ground plane from the ASIC) and BOOM within a second the chip was too hot to touch, current meter was pegged and I saw about 8GH reported on cgminer.

So it looks like I need to do some shifting around with the regulator circuit and see what might be done about isolating RFI from the ASIC. An initial test will probably be to stick a grounded metal shield between the inductor and the ASIC. Past that, maybe drill out the inductor pads and mount it on the back of the board, to see if putting it on the other side of a ground plane from the ASIC will do the trick. If necessary, we can make a double-sided board with the ASIC and its heatsink on the back. This might help make it a bit more compact, and though double-siding sucks we need to get good at it anyway for the TypeZero boards. Hopefully sandwiching the ASIC between ground planes and a heatsink will be enough to RF-isolate it from neighboring sticks' inductors in a fairly dense hub setting.

It's getting on quitting time now, but I might have more news tomorrow.

Edit - so shielding added a bit more stability, not a lot. I went ahead and stuck on a heatsink all proper, and it basically did things just as well as the shield. We noticed a lot of ground noise on the board that wasn't present with the external regulator attached. Tomorrow I'll probably drop on a higher inductor and see if the reduced ripple current cuts down on interference. If something like that won't solve the problem, we gotta go for a board redesign with better ground plane islanding - probably in conjunction with a larger inductor. The U2 inductor is 4.7uH to our 0.47uH and it's pretty much right up against the ASIC with no performance problems. We couldn't do with a 4.7uH inductor though, since we need to be able to handle probably 10A there aren't gonna be many options which are power-efficient and also not huge or expensive. But I'll test with one anyway, stolen off a roasted Block Erupter since we have a bunch of those. Should be good for 3A, which will do 600mV 125MHz testing.
The thing is running off the schfifty-three power board right now, and its own stock heatsink, on Eligius at the 1BURGER address. Should be at 125MHz churning out around 7GH. I'm really hoping I don't have to do another board design, because that'll shift things back another two weeks or so.

Assuming we let you. Remember what I said about not liking getting something for nothing?

Though the burger money thrown in so far could cover about 60% of our materials costs. There's no wage associated with this dev work, so it's almost been self-supporting as far as billed project costs. Novak's lucky, someone's actually paying him to do his job.

That's one reason I rejected the idea of a VIP front-of-the-line for shirt buyers, is it's too easy to exploit. But I don't really like the idea of getting something for nothing (I hesitated to put up the burger address) so that's why I figured the $4 discount on a miner. I didn't ask for the shirt thing, that was all whats-his-name's idea, but since someone's giving us money we didn't ask for I'd just as soon it was exchanged for equivalent product value. I'll probably do something with burger donations as well, where verified amounts of sandwich cash could be traded for stuff. We'll see.

Depends on implementation. All I can speak for is 150W per 8-pin, and the PCIe standard doesn't actually have provision for 2x 8-pin per card last I checked. I would not run 300W through 18AWG wire. I would run 300W through 16AWG wire, but I would never run more than 300W through a single PCIe 6-pin no matter what wire is behind it. But 150W through 18AWG is no problem at all.

No, I stand by what I said. It'd be fun to see someone hook one of these up to a Neptune thinking "oh, 1600W is plenty" and see the jackets on the 18AWG wires wilt off within a few seconds before the whole thing starts burning. The PSU itself might survive but not the cabling. It's a terrible idea (I can't in good conscience ever recommend anyone run Neptunes) but if someone does it I'd like to see video.

Be much less fun if it had 16AWG wires. 150W on 18AWG is probaby okay. 8-pin PCIe for GPUs are probably mostly 18AWG and those are rated for 150W by the standard, which means they're probably capable of more, and 8-pin PCIe only has three power leads.