When a worksheet contains sparklines, prior to Origin 2018b, all sparklines had to be drawn on project loading even if they were not visible. This slowed down initial rendering of the worksheet significantly.

A new system variable in 2018b addresses this issue by specifying how Origin should save EMF images of the sparklines:

@SIC=
0 Save all sparkline images in the OPJU.
-1 Don't save any sparkline images in project.
7000 (Default) If individual sparkline is < 7000 bytes then save it in the project.

Note: This system variable is persistant- it will be remembered across Origin sessions. It should be set from the Script Window or Command Window and not in the System Variables dialog.

When many graphs are shown and/or overlapped, complete rendering (painting) of all of them may take a considerable amount of time if the graphs contain a lot of data. Up until Origin 2018b, each graph had its own setting specifying that if 70% of the graph is covered it would not repaint. Now in Origin 2018b there is a system variable to change this behavior on a global basis.

@NPP=
0 (Default) Use existing setting in graph- same as old behavior.
1-100 Percentage that must be uncovered before repainting is triggered.
>100 (e.g.101) Only repaint the currently active graph. Do not attempt to repaint other graphs.

Note: This system variable is persistent- it will be remembered across Origin sessions. It should be set from the Script Window or Command Window and not in the System Variables dialog.