I've been using D3 linegraphs successfully with moderately large data sources (20K points) but now have an application that needs to display around 1M data points (3hours of 100Hz data).
Initially plotting the chart & redrawing in response to changes in the plot size takes around 5 seconds on an i7 based PC with a GeForce GT 330M graphics card.
There isn't much point displaying 1M data points when all data is displayed but when the user zooms in to a smaller region of the plot the high sample frequency data becomes useful.
I've considered showing the overview at 1Hz (approx 10K points) and then changing to higher frequency data (e.g. 100Hz) as the user zooms in.
Has anyone else faced a similar problem and what solution (if any) did you come up with?