Bitcoin Forum

Hi Folks,

I have a question on an FPGA miner design I am working on. Its running with CGMiner now at about 1GH/s, well, in fact it has 8 cores in it with each core running at 125MHz, so I know that each core is "hashing" at 125MH/s which is 1GH/s. However, sometimes it doesn't get a solution for a requested job from cgminer. That means that my average hash rate on cgminer drops down to around 750MH/s. Of course, sometimes it gets solutions very fast and shows my hash rate up near 4GH/s.

What is the story with the "no solution" issue and is there a better way to report hash rate in cgminer? Ideally, I would like to see always a 1GH/s worst case rate since that is what the hardware is running at.

Thanks

If each core runs at 125 MHz and can caluclate 1 hash per cycle your hash rate is 125MH/s. It seems however that the ICs you are using are not makeing a hash within a single calculation cycle.

Im not sure where your ICs find a shortcut in sha256 which is the only explanaiting I have to them something "solving" this faster.

Hi

The logic design has two SHA cores in it for each "hash" engine and runs fully pipelined. I can see in the simulation that the first hash takes 2 clock cycles, and then a new hash/nonce attempt is generated each clock cycle after that. It seems like that if no solution is found, that the code in cgminer drops the request and then its not counted as a hash attempt?

I just a single serial interface and no queue running. Maybe the issue is job-to-job latency? I need to implement the queue to make sure the chip has continuous work

You are talking about local hashrate, which is in your case 1 gh, but sometimes your luck is higher , sometimes lower, and that is what is making your miner appear on your pool sometimes as 750mh and sometimes above 1gh.