The Tartarus database contains products for 529ASCAobservations of active galactic nuclei. We have been updating Tartarus to include observing sequences conducted after 1999 January. The revised database will contain products for 375 objects, with a total of 614 observing sequences. We have begun a systematic timing analysis of the Tartarus light curves. We present here some preliminary results of an investigation into the relation between excess variance and black‐hole mass. Having optimised our analysis to minimize the scatter in the variance measurements, we find that the narrow‐line active galactic nuclei follow roughly the same relation as the broad‐line objects. © 2004 American Institute of Physics