<p>Give me the make of the FPGA and the name of FPGA binary you are using.</p>

<p>It could well be that you are over-clocking the FPGA too far, due to the way that many of these cores are designed, there is a race condition, where the  "success" flag, gets out of sync with the "nonce".</p>

<p>Basically the FPGA flags the "hit", but by the time it gets to copying the "nonce", it has changed......
and so fails.</p>

CC BY-SA 3.0
2012-12-10T02:56:14.410Z
2012-12-10T02:56:14.410Z
hardcore
<p>I am using an FPGA to mine bitcoins in a pool, as you can see below I am not really very successful:</p>

<p>[1 accepted, 48 failed, 148.90 +/- 21.27 Mhash/s]</p>

<p>It is running at 150 MhZ but I only have 1 accepted share out of 49. 
I guess this quota does not look to healhty. Anyone an idea what could
be wrong?</p>

CC BY-SA 3.0
2012-11-24T00:07:01.850Z
Is this a p2pool? Or perhaps a mining pool with a non-standard share difficulty?
David Schwartz
CC BY-SA 3.0
2012-11-24T10:17:16.880Z
Which miner software and version? And is the pool using variable difficulty ("var diff") ?
Dr.Haribo
CC BY-SA 3.0
2012-11-26T09:43:57.160Z
I am using this pool here: host = "api2.bitcoin.cz"
Patrick
CC BY-SA 3.0
2012-11-26T09:44:29.157Z
I am not sure what it means to use var diff, where can I find this out?
Patrick
<mining-pools><mining-hardware><fpga>
Shares mostly rejected mining with an FPGA
Patrick
# Shares mostly rejected mining with an FPGA

(Asked by: username_0 on 2012-11-23)

I am using an FPGA to mine bitcoins in a pool, as you can see below I am not really very successful:

[1 accepted, 48 failed, 148.90 +/- 21.27 Mhash/s]

It is running at 150 MhZ but I only have 1 accepted share out of 49.
I guess this quota does not look to healhty. Anyone an idea what could
be wrong?

**Tags:** mining-pools, mining-hardware, fpga

> **Comments:**
> **username_1**: Is this a p2pool? Or perhaps a mining pool with a non-standard share difficulty?  
> **username_2**: Which miner software and version? And is the pool using variable difficulty ("var diff") ?  
> **username_0**: I am using this pool here: host = "api2.bitcoin.cz"  
> **username_0**: I am not sure what it means to use var diff, where can I find this out?  

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## 1 answers

### Answer by username_3 on 2012-12-10. Score: 1

Give me the make of the FPGA and the name of FPGA binary you are using.

It could well be that you are over-clocking the FPGA too far, due to the way that many of these cores are designed, there is a race condition, where the "success" flag, gets out of sync with the "nonce".

Basically the FPGA flags the "hit", but by the time it gets to copying the "nonce", it has changed......
and so fails.


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