@ sidehack
I got your message, i just wanted to stay updated, probably like everybody else does
We're bidding the PCB etch, and I need to get back to heatsink people, so I should have a final BOM and price estimate (assuming my current design works properly) fairly soon. We're finalizing lists for who we'd like to send prototypes for to be evaluated, and I'll probably be sending out some messages tonight to verify with folks. There might be delays on the Compac protoPCBs but they should ought arrive with plenty of time to test things and still be reasonable.
Fairly soon means, 2 days, 2 weeks, June 2015?
Well, don't expect a batch to be shipping before June. It's minimum 3 weeks from now before we even start talking seriously about taking in preorder money. That gives time for proto PCBs to arrive, for us to in-house test, to get some to outside testers and them to report. That's assuming the proto PCBs work. If the design is solid and the supply chain is laid out, we'd probably take two weeks to gather money for a batch and then place orders for materials which would be three to four weeks out. After that, assembly and testing and shipping probably aroudn the end of June (at the earliest). There's plenty of time to gather hubs and such.
Minimum 3 weeks is like in the beginning of CW 22/2015?
So Novak and I have been rolling around an idea for a miner since about December. We were inspired by ASICMiner's BE300 sample chip test results and thought we had a pretty solid idea for a machine built around them.
Unfortunately, AM's BE300 doesn't really exist outside of those test chips, and it's quite probable it never will.
Bitmain's BM1384 (the chip inside the S5), however, is a fair substitute. Its bottom-end power efficiency compares to the BE300's midrange, the core voltages are a bit more manageable and the chained comms setup appears to be easier to work with. We ended up buying some sample BM1384 from Bitmain and the chips arrived on Monday, so now we can start playing with them. The datasheet is incredibly sparse regarding any kind of protocols, but fortunately the signalling appears to be identical from the BM1380 (S1/S2/U1/U2) and BM1382 (S3,S4,U3) so it shouldn't be too hard to figure out.
I did a bit of prodding on an S5 yesterday and got the comms topology and level-shifting pretty well figured out. Some prodding on a U2 has given us info on USB interfacing to the chip chain. Novak's tearing into U3 cgminer drivers to iron out data specifics and I'm going to work on the regulators and digital IO requirements.
The next step, which I'll be working on this afternoon, is to design a simple BM1384 breakout board that consolidates power lines and puts signals on a simple header. With a two-chip board on independent planes we can test one-chip comms, parallel node comms and string comms to get a basic understanding of topology changes.
It occurred to us that a simplification of this breakout board could be an effective USB stick miner which might be capable of 10GH around 3W of draw. We may design a PCB for this if there's enough interest.
The primary goal is to build a simple board which would be USB-connected to a controller, and capable of adjusting both core voltages and clock speeds using cgminer flags. We're looking at a single board capable of 300GH at 150W, downclockable to around 150GH 50W. At mid- or low-range settings it could be run off a brick with a quiet 120mm fan and heatsink and be a decen Jalapeno-formfactor home desk miner. The board will be designed specifically so that four of them would mount to an S1 chassis. Couple that with a 4-port USB hub and a Pi or something as the controller, and you have an "S1 Upgrade Kit" which will aim for 1.3TH at 600W clockable down to 600GH about 160W. These are board-level power estimates. This board is codenamed "TypeZero". We're trying to iron out a design that would incorporate the overall efficiency (both in power and cost) of string topology and the flexibility of standard VRM topology. Basically we're trying to take the best parts of several decent designs and make one thing that should be modular, flexible, reliable, affordable and efficient. Lofty goals to be sure, but hey why not aim for the top?
A secondary goal would be to design another board which could mount to a Prisma chassis. Modifying our design to a similar power density as a Prisma (1KW board-level) we could see a 2.4GH miner downclockable to about 1.1TH at 300W. There are other prerequisites to meet before considering moving forward on this, however.
We're a pretty low-fund operation these days, but we have some big jobs coming in which might be able to provide capital for a batch. In the worst case, we might try and open a preorder (grumble grumble) once we have a tested working prototype and solid final design. Manufacturing feasibility is going to depend heavily on the chip cost from Bitmain. With the "upgrade kit" savings of not having to manufacture heatsink chassis and controllers (and then pay to ship it all everywhere), the bulk of BOM expense is going to be ASIC costs, most likely. We've always liked doing things for home miners, and trying to keep prices fair, so we'll do our best to get these things made in a way that doesn't suck for everyone.
If it takes forever for anything to happen and Bitmain's already out of BM1384 and selling the BM1386 or whatever, it shouldn't take much to modify the design for the new chip. Assuming they don't make major changes to the comm protocols, which they haven't done yet so that's encouraging.
So, questions? Comments? Sandwiches? We're not really getting paid to design all this stuff so "keep up the good work" sandwich donations are more than welcome (1BURGERAXHH6Yi6LRybRJK7ybEm5m5HwTr).
Are you still tending to use cgminer? Are you still sticking to the S1/3 chassis for mounting your boards?
I really do not mean to give you a hard time, but honestly, i can't wait to get my hands on these boards!!!
Keep it going, and in the meantime enjoy some angusburgers