Topic: FPGA ghetto mining / hunting for fpgas on ebay - page 2. (Read 7101 times)

  That's what I was wondering. They are almost twice the I/O but are 65nm and lower voltage. IF they can't run the same speed as the S6 then, as you say, we would not get twice the hash. You can buy an S6 -N3 quality for $158 now.


  Edit; Those second ones are a smaller package, 456 pin.  Though, with those at $2.5 per chip. If you could even get 1/4 of them in good condition with reballing might be worth messing with.  Not sure what hash they are capable of. Someone that knows what they are reading should be able to guess from the cell and i/o count on them though.

Cheaper than new but not worth it. Propably it may achieve somwhere around 150MH/s. New Spartan6 LX150 (175$ and will work for sure) can do more.

BTW. Those XC2V250 may achive somwhere near 1MH/s...
Worth to look are Virtexes 5 and 6, preferably 110+ at prices around 100$. Best buy will be XC6V240T (400MH/s possible).

   Those first ones are almost twice the I/Os of the ones being used now. They appear to be 1136 pin verses the 484 of current design. They are lower voltage than the 484 package, being 1v instead of 1.2v.   However a LOTTTT cheaper on this ebay auction than new.

  http://avnetexpress.avnet.com/store/em/EMController/Programmable-Logic/FPGA/_/N-100235/Ne-100000?action=products&cat=1&catalogId=500201&cutTape=&inStock=&langId=-1&myCatalog=&proto=®ionalStock=&rohs=&storeId=500201&term=XC5VLX110T&topSellers=

The first board's origin is kind of interesting, it looks like it's a custom board from a company that pissed away $16 million+ in venture capital in three years. Their site is all buzzwords: "Blackwave designed and built the first purpose-built video streaming appliance. Precisely matching intelligent proprietary software with industry standard hardware, Blackwave can drive higher performance while occupying less floor space and requiring less administrative oversight and power consumption." Here's a list of their Management Team archived before the domain expired, so you know who not to hire.

I've try that. No can do... 1mm spacing is to small. I've used a chipset from damaged matherboard. And I'm rather experienced in soldering (11 years in work and other 10 as a hobbist).

fail.


looking at those pics from ebay, those chips look beat to hell.

There seems to be quite some possibility to acquire fpgas on ebay.

Most of them are from damaged boards where you would have to reball them yourself, but I think we woudn't necessarily need that.

My thought is get them off the board with a hot air gun and glue several of them on a big heatsink upside down with a heat-conducting glue.
They possibly couldn't be used for anything else after that but what the hell, they are most likely living their rest of their lifespan generating bitcoins anyway...

Then solder wires directly onto the pad were the reballing would take place, that could be quite difficult but I think it would be possible.
The optimal way would be to devise a system were a minimal amount of wiring is required, only jtag + serdes nodes to get the data though. (or possibly even with the jtag backchannel, would be even more awesome)

The only real isse I see here is supplying power, since they sometimes require different levels and designing differnt power converter circuity everytime would not be very efficient and would require too much work.

Possible sources:

http://www.ebay.com/itm/Xilinx-Virtex-5-XC5VLX110T-64-x-Samsung-XCK9F8G08U0M-PCB0-8GB-Chip-Recovery-/260871631798?pt=LH_DefaultDomain_0&hash=item3cbd2933b6
(might be a good board in case anyone wants to grab it and run with it go ahead)

http://www.ebay.com/itm/Lot-100-pcs-XC2V250-5FG456I-Xilinx-PCB-BGA-FPGA-/270846090663?pt=LH_DefaultDomain_0&hash=item3f0faf5da7
100 small small old virtexes, might work without unrolling.

What we also would need is a design which can be quickly adopted to many different chips with different I/O configurations.
I think if this works out this could very well be the next big thing in bitcoin mining...