Topic: Buying FPGA on eBay - page 2. (Read 4445 times)

If you want to run fast and efficiently on an FPGA, you need to maximize clock rate, and throughput rate.  This essentially means a hash every clock cycle, and you fully pipeline the design (which introduces latency, but preserves throughput) to run at the max toggle rate of the FPGA.

A fully pipelined, and unrolled SHA256 engine with routing will probably run you around 150K logic cells.

If you run at 200 MHz, then you should get about 200 MHash/second per 150K logic cells.
(This is about the specs for the various Spartan 6 LX150 boards out there).

You won't find these boards for $50.

The closest is this one (4 LX150's running at 800 MHash/sec) - for $1069.99
http://modminerquadstore.com/index.php?route=product/product&product_id=50

I'm looking at putting together a dual Cyclone V based FPGA board.  This is 28 nm technology, which means I should be able to run at 250-300 MHz, and the chips are 301K LC each, so I should be able to run at about 1000-1200 MHash/sec.  If I get it going, I'm thinking of shipping units at $900 per 1000-1200 MHash/sec.

http://www.raspberrycoins.com/

There's an FAQ I put together at : http://www.raspberrycoins.com/fpga_miner


The thing is, there is this thing called ASIC mining which may be around the corner (but it's been around the corner for several months), and if it comes into being, will run faster, at a lower cost than FPGA mining.

But in the mean time, there's bitcoins to be mined at the current difficulty level, so I want the bring the question to the general market.
If it makes sense to mine bitcoins with the latest FPGA (and thus get a speed boost), let me know by registering.  If we get enough registrations, then, we'll do a crowd source funding and make some boards (delivering boards + software to our funders).

I'm essentially putting it up to the collective wisdom of the crowd to determine if it makes sense to mine bitcoins with FPGA's.

Best Regards,

Tony

It is not worth it.

Consider that even if you pick up a V5 110 for about $50 bucks

Jobs

1. trace out circuit in an attempt to find where to tap into FPGA
2. Hope to GOD that :
A. The vias you need on the pins are big enough to be soldered
B. The important pins are not tied to gnd or to existing circuit
C. There is a clock circuit and it is accessible
D. you design Suitable USB/RS232 I/O
E. The PCB powers up.

OK you have a rewired working PCB

1. System to LOAD the FPGA
2. mining software to support the IO YOU have to design
3. Layout of existing scrap PCB is suitable for the power & frequency you need...


Hurray.... step 3

Design a switched mode PSU to handle the kit, yep the PCB *may* have SM on it, but you still need to supply that with the output of another power supply..


Step 4  hurrayyy.......

You are mining @ 100-200 Mh/s


In several months you can make your $50 bucks back.......

If you have 1.7GH/s you can make 10 bucks a day when bitcoin is at 100USD each....



I have this down to a fine art....  (I can build a  2GH/s rig in a DAY!!!)

Even buying FPGA at $30USD each.... it is barely worth it with the difficulty changing 10% twice a month.....

It needs to say Bitcoin FPGA, if it don't it's just for an electronics project. 

 There are lots of fpga looking things on eBay , how can I know if they are any good for mining ? What specs should I be looking for?