I have been setting up node with parity kovan testnet on cloud instance.I want to start mining with ethminer.

When I start mining with:

ethminer -C -F ""

gives error as:

miner  06:39:47.443|ethminer  Getting work package...
JSON-RPC problem. Probably couldn't connect. Retrying in 1...

And starting with:

ethminer -G -F ""

gives error as:

[OPENCL]:No OpenCL platforms found
No GPU device with sufficient memory was found. Can't GPU mine. Remove the -G argument

With geth I can successfully start mining on same cloud instance but can't with parity.

Starting parity with:

parity --jsonrpc-port "8545" --jsonrpc-apis "all" --port "30303" --chain=kovan --author (address of coinbase) 

How could I fix the error I am facing?Thanks in advance.

1 Answer 1


Before even looking into the miner issues: Kovan is a Proof-of-Authority network. You can not mine a PoA-network with traditional PoW miners.

Geth does not support Kovan either, by the way. If you want a testnet that works for both clients and allows PoW mining, have a look at --chain ropsten.

  • Thanks for answer.Yes you are right.I am running geth with ropsten. So able to mine with geth.
    – HARESH
    Sep 1, 2017 at 9:53

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