SETI@home is 20 times more sensitive to narrow band signals than SERENDIP, because the enormous computing power provided by the SETI@home volunteers allows the SETI@home screensaver client to compute coherent very long duration spectra on tens of thousands of possible signal drift rates. The SETI@home client also searches for pulses, signals with several different bandwidths, and signals that match the telescope beam patterns. An auto-correlation algorithm is used to search for repeating patterns. Although SETI@home is more sensitive than SERENDIP, and searches for a very rich variety of signal types, we probably won’t be able to record and process the full bandwidth of all the beams at FAST (recording 80 Gbits per second for several years is a lot to manage). So SETI@home would likely process a part of the FAST multi-beam receiver band at very high sensitivity, while SERENDIP6 would process the full band at a reduced sensitivity. Longer term, FAST is planning a sensitive phased array feed, which could provide roughly 100 simultaneous beams; excellent for a next generation SETI sky survey.

More generally, Earthlings are just beginning to learn how we might detect other civilizations if they are out there. We’ve only had radio technology for a 