Hi,
I have been testing in Delphi 11, which has GDI+ enabled by default for TChart. I suppose that Delphi 7 does not have the BeginUpdate & EndUpdate as well as GDI+ disabled by default. TAdvChartView (GDI) or TAdvGDIPChartView (GDI+) is designed to load large amount of points with BeginUpdate & EndUpdate, has the ability to interact with it, but then needs limited amount of visible points. Of course, interaction can be turned off with EnableInteraction to avoid the performance issues when hovering over the chart, but when interaction is required, the amount of visible points needs to be limited (as explained in one of my previous posts). Unfortunately it's still unclear now if you need interaction or not. There are solutions for both cases, but the approach differs. Additionally, GDI+ disabled TeeChart will of course load faster and work better than a GDI+ enabled TAdvChartView (TAdvGDIPChartView). GDI+ is asking for a lot more resources in comparison with GDI.