I have a question which is closely related to this one: FFT Processing Gain
^that discussion is a bit general so I want to ask a very objective question to see if I can apply that knowledge:
If I collect one million time samples and perform a one million point DFT, roughly what DFT processing gain (in dB) improvement can I expect to achieve in pulling a weak spectral component up above background noise in comparison to a 100 point DFT?
I guess that answer is 100,000. isn't it?
we have 9999910 more bins.