Sepolia is now on PoS
As of 2022/7/6, Sepolia has switched to PoS. The window to do some mining has closed.
Testnets after merge (original, old content from here)
It's mid 2022, Ethereum is still PoW and motoring towards merge / PoS. Surviving testnets will be Sepolia - currently PoW - and Goerli. Ropsten will be merged and then deprecated, Rinkeby and Kovan won't be merged.
I want to "get ready" for some Sepolia testing pre- and post-merge. Sepolia will not have a public validator set; testing post-merge will be limited to running applications on it. As Sepolia is PoW, I can actually go mine myself some SepplETH. Here's how.
- Geth on Sepolia, Linux. This could absolutely be Windows, I just happen to have Linux tooling I like
- ethminer or t-rex, Windows, with an NVidia or AMD GPU. Mostly because the only GPU I have that can mine is in my Windows box
Set up Geth
I'm using eth-docker for this.
sudo apt update && sudo apt install -y docker-compose
Make your user part of the
docker group so you don't need
sudo for docker commands:
sudo usermod -aG docker MYUSERNAME && newgrp docker
git clone https://github.com/eth-educators/eth-docker.git sepolia && cd sepolia
Configure eth-docker for this:
cp default.env .env, then
nano .env and set
Save and close.
Get the ETH address you want the Sepolia mining rewards to be sent to. Anything created in Metamask will do.
A few changes for Geth so it can mine.
nano geth.yml and change the
entrypoint. Enable the
miner API, and append to it:
entrypoint: - geth .... existing entries, leave those be - --http.api - web3,eth,net,miner .... existing entries, leave those be - --pprof.addr - 0.0.0.0 - --mine - --miner.etherbase - "0xMYETHADDRESS"
You need the quotes around the address, and
0xMYETHADDRESS is going to be your actual address.
./ethd up, and look at the logs with
./ethd logs -f execution. It should sync the chain in minutes and then be ready for mining.
If your Linux boxen is on the Internet, not in your home network, and only then, you'll want to firewall the RPC port 8545 and WS port 8546, which are both exposed now. Follow instructions to place ufw "in front of" docker, get the public IP your Windows box uses with something like whatismyip and create a simple policy along these lines:
sudo ufw allow OpenSSH sudo ufw allow proto tcp from MYPUBLICIP to any port 8545 sudo ufw deny 8545 sudo ufw deny 8546
sudo ufw enable. Adjust the policy to your own needs if you already had ufw running.
Connect Metamask to Sepolia
In Metamask, go to Settings, Network, Add Network and create a new custom network.
Sepolia Test Network, set the New RPC URL to your Sepolia Geth as
http://IP-OF-GETH-BOX:8545, Chain ID
11155111, currency symbol
SepplETH and Explorer to
Your AntiVirus and browser will likely quarantine these as cryptominers, because they are. You'll need to allow-list them.
Grab ethminer. It's open source, but doesn't work with newer-generation cards. A PR that enables CUDA11 and thus RTX 3000 series does exist, but there are no ready-made executables for it.
Extract that somewhere, get into a PowerShell or create a bat file, then start it like so: For NVidia,
.\ethminer.exe -U -P getwork://IP-OF-GETH-BOX:8545 or for AMD,
.\ethminer.exe -G -P getwork://IP-OF-GETH-BOX:8545.
You can get help with
An alternative is t-rex, which is closed-source. It takes a 1% dev cut, and supports newer-generation cards. Download it, then run it in PowerShell or via bat as
.\t-rex.exe -a ethash -o http://IP-OF-GETH-BOX:8545.
You can get help with
In my testing both ethminer and t-rex get almost the same hashrate from GTX 1080 and GTX 1070, with T-Rex ahead by maybe 5%. T-Rex does have a nice UI.
In your Geth logs, you should see
🔨 mined potential block and
🔗 block reached canonical chain as well as the occasional
⑂ block became an uncle, and in ethminer you should see
Enjoy the feeling of early Ethereum mining. Difficulty on Sepolia is low, you should see rewards come in steadily.
Which is more than enough. Gas on Sepolia is cheap. That's enough for a ton of contract deployments and testing.