I have a spare computer with a fairly decent CPU but no graphics card. I like the idea of running an ethereum node just for the warm feeling of being involved. Two questions:
1) If I use this machine as a miner will I be contributing anything useful to the network?
2) Is it possible to run as just a kind of block verifier that is providing useful work without having to do PoW?
Or, in general, can a machine without a beefy GPU contribute anything useful to the network?