Probe is a visual performance monitor measuring CPU times of processes running TouchDesigner.
There are forum posts at https://www.derivative.ca/Forum/viewtopic.php?p=30059
See also the non-graphical monitor: Performance Monitor
How to Use probe
probe component from the Palette anywhere in your TouchDesigner process.
Pressing Ctrl-p will display and un-display the probe panel: You will be able to see the probe when you are in Designer Mode as a floating window, or in Perform Mode as a panel embedded in your main UI.
The probe panel looks a bit like your network. Each stack of circles represents the recent time-history of a node. There is one stack for every node in your current network. The color and size of the circles gives the cook time... use the color legend at the bottom left, expressed in milliseconds.
Each stack is 10 circles, the top being the most recent Time Slice that cooked, the bottom being the tenth most-recent Time Slice. However if a node hasn't cooked in the last 10 time slices, the bottom circle represents the most recent time it actually cooked.
Navigate the networks by left-clicking on a node's box, assuming it's a component. Click on the background to go up the network hierarchy.
Middle click on the node to bring up its parameter dialog. Right-click on a node to bring up another window containing the network editor for that node.
The stacks that look like donuts or Tootsie Roll (USA) that have a circle within a circle are components. The inner circle represents the children cooking inside the component, the outer circle representing the sum of the node's cook time and its children's cook time.
The large colored box around all the nodes represents, through its color, the cook time of all the nodes in the network, including all children.
Like in the standard Performance monitor, the OP cooking you see is for the CPU times, not the GPU times. TOPs and panels are the only OP families that uses GPU, and the cook time you see for them is only the CPU set-up time. (same is true for the Dialogs -> Performance Monitor)
This component consumes its own cook time, sometimes a few milliseconds, so it will slow your process down a bit when it is being displayed.