When you select the section Preferences > Menu Bar Layout in the sidebar of the control window, you can define settings that become effective for all monitor items in the menu bar.
To always keep a control menu for System Monitor accessible at a known location, the application attaches such a menu to a small version of its icon in the menu bar. This icon consumes real estate in the menu bar, however, although it has no other useful display features. If it is more important for you to save space, especially on small screens, than having direct access to the control menu, you can remove this icon from the bar. Set a check mark at Suppress application in the menu bar.
You need to confirm this explicitly by using this layout option. You cannot remove the icon by dragging it out of the menu bar.
When the icon is no longer visible, you can control the application via its normal main menu that activates when you switch the program to its full user interface. You can use any of the Preferences… menu items in any of the other menu-bar items of System Monitor to do that.
Space in the menu bar can be limited, especially when using small screens. To save some real estate, System Monitor can be forced to omit the display of places behind the decimal point for all large numeric displays shown in the menu bar. You can select between the two items
Percentage and temperature values are usually displayed with one digit behind the decimal point. This setting has no effect on bar displays containing two lines.
The widths of graphs shown directly within the menu-bar area can be specified as well. They can be set independently for history graphs and bar graph displays. The widths can be set infinitely variable, decreasing the size down to the half of the standard size, saving screen space. Similarly, you can also extend the widths up to double the value of the normal sizes, in particular to recognize more time details within history graphs.
To do this, move one of the sliders within the box Widths of variable objects either in the direction small or large. The left slider controls history graphs, while the right slider controls bar graphs. The change will become visible in a sample bar and also takes effect on the menu bar immediately. Clicking the button Set default will return to standard size.
The time intervals shown in history graphs will always be the same. Only the graphical presentations will be stretched or compressed.