The Stats tool

Stats: CPU, memory, disk and network at a glance

The numbers you glance at when your Mac feels slow, without a menu bar full of meters.

CPU with a live graph and core count.
Memory used and total.
Disk free space.
Network down and up.
Battery and charging, on laptops.

Plug in your charger and the notch shows the level for a moment; it warns you once when the battery runs low.

Questions, answered.

Does it slow my Mac down?

No. Stats only samples while the panel is open.