I'm mining Testnet now! It's CPU only, on a server. Let's see if it catches a block.
It's been 4 days, and at 6.33Mh/s, I haven't found a single block. Maybe I did something wrong, or maybe CPU mining is still too slow even when the difficulty is 1.
I killed the miner, it seems like a waste of CPU. But I'll keep Bitcoin Core Testnet running for a while.