Is it normal for EOA to EOA ether transfer to cost over 21000 gas without data?

Question

In a private testnet, I sent some ether from one external account to another. There is no input data. It cost 24,000 gas, instead of 21,000. Is this normal?

> web3.eth.sendTransaction({from:eth.coinbase,to:"0x0000000000000000000000000000000000000001", value:3000000000000000000})
"0x7e55fd8ffc1a150f30ca5f5845b6e3af3507b3443d326e1d755748864886bcf7"

> eth.getTransactionReceipt("0x7e55fd8ffc1a150f30ca5f5845b6e3af3507b3443d326e1d755748864886bcf7")
{
  blockHash: "0x90cbda119916bfd9a481a9eedec6af74bce6ac4f6e8c3d7ccf6ea4a13038d5d7",
  blockNumber: 24073,
  contractAddress: null,
  cumulativeGasUsed: 24000,
  from: "0xf6de496ec5601d74937ddd77af09c8cd4ba41ab5",
  gasUsed: 24000,
  logs: [],
  logsBloom: "0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
  status: "0x1",
  to: "0x0000000000000000000000000000000000000001",
  transactionHash: "0x7e55fd8ffc1a150f30ca5f5845b6e3af3507b3443d326e1d755748864886bcf7",
  transactionIndex: 0
}

Answer 1

This is probably because the address 0x0000000000000000000000000000000000000001 is actually a precompile, meaning it is a contract, so it'll cost more. It's the ECDSA recovery contract. For more information, see Appendix E of the yellow paper at https://ethereum.github.io/yellowpaper/paper.pdf.