Also one of the intelligences encountered in Diaspora by Greg Egan. Actually, they just meet a localised handling agent that explains that they work for a star

Also one of the intelligences encountered in Diaspora by Greg Egan. Actually, they just meet a localised handling agent that explains that they work for a star-spanning sentience - which is something the characters had been considering as a way of making themselves robust against civilisation-destroying gamma ray bursts, but dismissed on the grounds that it made everything so slow - though that links into the other theme in that book of simulated beings existing on very different timescales.