Interval Setting:
The interval setting is shown in the image below:
This represents how often to check planet positions and heliacal phenomena, etc. The more often you check, the more accurate the graph will be, but at the same time the slower the drawing of the graph. The recommended setting is daily for graphs that calculate less than 5 years. If you are calculating heliacal phenomena for a short range of time then the 1/4 day setting is recommended. If only outer planets are being drawn, say Jupiter on out, and for a period of 10 years, then weekly or monthly becomes a viable option and will speed graph drawing significantly.
The speed of your processor is relevant here. On my pentium M, 1.8 Ghz laptop with 1GB RAM, the drawing for a year long graph takes about 2 seconds at the daily interval.
