I am not sure it is possible to calculate it, since it depends on many factors, such as what else is in memory and what you are doing with the data in SignalExpress. In addition, SignalExpress is a 32-bit application, so cannot address more than 4GBytes of memory. In practice, you will probably hit memory limits in a moderate project somewhere between one and ten million data points. This does not apply to logs, since they are on disk, but may apply to playback of logs, since you need the data in memory to do anything with it. Once again, depending upon what you are doing, how many steps you are using, etc., you will be able to access more or fewer points.
