Second, I was surprised by reaction about comparision with ButterFly Labs with 'Estimated price'. People, that's $90k is with 20% VAT, which is not paid in US for example and with having in mind that it would have single hot air outlet and that's all about it... but to get mini-rig we would pay +20% on customs VAT, so it would be not $15'295 but $18'354 + shipment costs,
Remember, US customers don't pay VAT, so you've probably quoted a EU price that is useless for US customers. If you can get BFL Minirig prices on Spartan 6 hardware, BFL is screwed.
Well, if we count on bulk purchase by miners directly via assembly house without any intermediate - then BFL is blow
away definitely. As BitFury-110 was built for less money than BFL asked, if consider that we pay VAT. And it is not possible to bring such quantity of BFLs through customs and declare them as personal items when nobody cares.
Third, 300 Mh/s is not limit of this bitstream, it can give even more rounds, if you count that almost all DSPs are not used in left part of design, and some free space in topmost part. So it could definitely give 8% at least better performance, it would then cost to us $0,57 per Mh/s, which is even less than BFL Mini-Rig.
Someone said in another thread that the sea of hashers design will have three types of cores, ones near DSPs, one near BRAM, ones near neither.
There's already three types, more or less common however. One difficult piece is 28-bit adder in the middle as there exists cuts for PLL/DCM modules of slices. It was tricky to implement, but done.
I've been asked by email and skype about smaller editions. And I would say that in my opinion best solution would be standard 4-U chassis, 0.5 meter long, with 14-15 boards with 6 chips on board installed (that is 84 - 90 chips), like with shalab.si original ideas, but a bit different layout to prevent overheating chips.
That gives people mostly what they want.
Yep, and my initiative is to make things more or less compatible. Why to invent multiple fancy form-factors with fancy fans ? When it would be nightmare to support it for miner ? Mining is not that profitable - to play with the equipment long days and nights. Unfortunately instead of getting here exact numbers / requests / discussion about future design, we have more common discussion. Every designer still wants to invent own kind of wheel. I understand this of course, even for myself - because every developer thinks that he understands details better, which is actually true... But when it comes to maintenance - it is better to have simpler things as MOST RELIABLE THING - IS THE THING THAT DOES NOT EXISTS.... So there's tradeoff between creativity and will to produce maintainable and reliable devices.
Withing this chassis single Intel Atom D525 motherboard is installed. Boards with 6 spartans can be even without microcontrollers and flash, everything could be programmed right via LPT-port. Bandwith required to communicate with every chip is quite low - about 300 bps. So with all chips it would be about 27 kbps. Bitstream loading over LPT port however will be slow. For smaller scale RS-485 is overkill. Why to bother about it and not implement using USB - simply because flashing chip or flashing controller
adds up cost of controller and also costs of programming and testing them, also when something should be updated, and you have to reprogram every controller - that rises service cost. I would like to say, that current design of BitFury rack, where controller only translates RS-485 to SPI bus with Spartan and back requires almost zero maintenance.
Use SATA plugs for the actual connector, but normal serial over it. SATA has 7 pins and is enterprise ready. The cost of serial is the complex plug, not the actual design. You could use a very tiny FPGA for the controller on each board to interface with the serial using GPIO pins or something.
SATA plugs! thanks, nice idea! 4-in cables are there.... This as simple as just installing proper size of SATA PCB layout on PCB! $1.67 x 16 = $26.7 for all of the connectivity. Just connecting each board to another one. Simply installing them and connecting. 1.6m long wire.
http://www.satacables.com/About controller - I've mentioned only 500 bps per chip, so for 90 chips it would be max. 45k bps in and out...
Information about protocol is avail in initial post. So pinout can be following:
PIN1 - SCK
PIN2 - MOSI
PIN3 - MISO
PIN4 - GROUND
PIN5 - RESET
PIN6 - PROGDATA
PIN7 - PROGSCK
So it would be possible (a) upload bitstream (b) reset all chips (c) send/receive work.
OR - ANOTHER POSSIBILITY IS TO USE JTAG (but I don't know actually how well it work via such long chains like 90 chips, even when TCK, TMS will be transmitted using buffers.
PIN1 - TMS
PIN2 - TCK
PIN3 - TDI
PIN4 - GROUND
PIN5 - UNUSED
PIN6 - RST
PIN7 - TDO
Please not that key is not important, as improper insertion of cabling won't fry things. However it would be
perfectly possible to transmit jobs over JTAG. JTAG also seems to be nicer, because key can be programmed into board right using this slot.
So single SATA and single power molex. Are there cons in JTAG vs 2 SPIs ?
Cost of such chassis with power supply and Intel ATOM motherboard could vary in $400 - $600 range. Cost of Spartan6 chips when purchased in bulk quantities (WITHOUT VAT) would vary in $70 - $95 range, depending on shipment location and quantity of chips ordered. Cost of other components (using numbers from our current design):
No. Use something smaller and lower power to run this, not some shitty Atom board. Use a Pi or that new $50 Via x86 board
http://www.geek.com/articles/chips/via-launch-a-49-android-pc-20120522/Nice board, is there any other boards that support GPIO for example or SPI or JTAG output without any additional converters ? So I could launch software on linux ? That would be excellent for this project. Possibly with 2 cores, so one core could drive GPIO in realtime manner, while other core is communicating with world. But not necessary, as SPI tolerate lags!
200 Mh/s bitstream - would produce 18 Gh/s - it would be compared to 71% of Mini-Rig and so product price could be $10'859.
250 Mh/s bitstream - would produce 22.5 Gh/s - it would be compared to 89,2% of Mini-Rig and so product price could be $13'643.
300 MH/s bitstream - would produce 27 Gh/s - it would be compared to 107% of Mini-Rig and so product price could be $16'365.
325 MH/s bitstream - would produce 29.2 Gh/s - it would be compared to 116% of Mini-Rig and so product price could be $17'722.
Remember, if you're overclocking these, provide some way to underclock+undervolt these to extend the life of these once diff goes too high in 3-4 years. This is a big feature that a lot of people are asking for.
These are not overclocked, overclocking could give +20 - 25%, but will consume more power and possibly damage chips permanently.
Also, another thing, make sure the total power usage for the box fits so an integer number of these fits on a 120v 20a (the most common circuit in DCs, you often get two of these per rack). ~1000 watts each would be fine if you intend on putting two on a circuit.
Well one box 4U would consume about 1.3 - 1.5 kW power that's 10,8 - 12,5 Amps @ 120 V seems to be bad.
With 11-12 boards it would be not more than 10 Amps @ 120 V however.