Mining Testnet Bitcoins Without ASIC

Got a new guide for everyone wanting to solo mine testnet bitcoins without an ASIC. Now you can do it with just your CPU or GPU. Should work on most laptops or desktops, even those new Apple M1 chips. Just remember, faster hardware increases your odds of finding blocks.

Compiled bfgminer after some digging for dependencies on my OS. One thing though, it doesn’t play nice with Bech32 addresses, but no major issues aside from that. Testing my mining efficiency now over a few days.

Yeah, missed mentioning it earlier, but bfgminer needs legacy addresses. Good luck mining with your CPU or GPU! Just an FYI though, it’s much slower than using any ASIC, even a small USB one.

Important note: Testnet coins are totally worthless. They're meant solely for testing software, not for cashing out. Mining and holding these coins? Pretty pointless since Testnet forks happen regularly, making old coins unusable.

Didn’t mention it since I assumed most users know that. But yeah, for those newbies here, testnet bitcoins are worthless. They're just for testing projects without relying on faucets.

After about 4 days, I mined 4 blocks, but two went stale thanks to my slow internet. Not bad for ~0.05 tBTC. I plan to use that for testing some OPCODES or maybe donate it back to the faucet.

Ran into some issues trying to repeat the process. Here's what I did, and I think I got the connection right, but bfgminer still acting weird.

You're probably using different settings in bfgminer than I suggested. Check if you're allowing getwork and stratum connectivity. Might be why it's not working.

Yeah, set those options intentionally. I was hoping bfgminer would work for getblocktemplate mining, but cpuminer seems more reliable so far.

Glad the guide helped! I'm currently mining on Testnet with just my CPU on a server. Fingers crossed for that first block.

Also noticed bfgminer’s proofs don’t seem to generate more than 8 leading zeros. Can we tweak it to aim for more?

For what it’s worth, I had decent success using cgminer on AMD GPU recently.

After 4 days at 6.33Mh/s, I still haven’t found a block... might be too slow, but I’ll keep the Bitcoin Core Testnet running.

Shut it down after a week, restarted it this morning. Let's see if anything changes this time.

Rough math suggests if you’re at 300GH/s with diff 1, you’d find a block super fast. Feels like something’s off if I’m at 6MH/s and still getting nowhere.

Who came up with this 20-minute reset anyway? What’s with the difference in timings on Testnet blocks?

Good point. I read the 20 minutes became standard back in 2013, thanks to Gavin Andresen. Seems like it’s changing around testing networks as well.

Did you keep an eye on your CPU miner? I caught it at one point where the last block was ages ago and bfgminer didn’t adjust difficulty.

I meant the bfgminer log output. Does it show if it realized it hit the difficulty 1 mark or just carry on oblivious?

Could be why it’s struggling to mine blocks. If it doesn’t recognize the easy difficulty, then it might not find anything. Assuming difficulty=1 doesn’t mean instant blocks.