Why are there inconsistencies in the memory profiler as well as memory profiler and task manager?

The Tree Maps and default Table underneath it is filtered to show all memory used by Objects, native or managed. There are also non-object associated native allocations and preallocated pools and buffers. The Fragmentation Page, the All Native Allocations Table and the All Memory Regions Tables give a more complete picture of memory usage, albeit less concrete in terms of items one usually encounters within the Editor.

To give you a better explanation of what might be going on with your discrepancy between the total used in the tool vs Task manager it'd be good to know if your, as it sounds, using windows, which Unity version you are using and what that memory usage overview looks like for that snapshot.

Generally speaking though, is this something we are working on closing the gap on, including the Untracked part. What could constitute the Untracked amount is displayed in the Memory Profiler windo when you select that bar or the row for it.

 

to add to what Martin said:

• TreeMap displays only a portion of memory attributed to UnityEngine.Objects and managed C# objected
  • We'll updated it to display all memory we know about it in the coming releases.
• Task Manager and Memory profiler relation is not 100% clear
  • There are 2 important concepts to know about - Working Set/RSS and Committed Memory
    • Working Set is the portion of memory app has in physical memory - https://docs.microsoft.com/en-us/windows/win32/memory/working-set
    • Committed Memory is the memory allocated by a process and that maybe in physical memory or swap file
  • You need to know both actually
    • Working Set defines the app "memory pressure" on the system and may be a metric of how likely the game is going to be killed by OS
      
    • Committed memory allows you to see all allocations and understand whether or not Unity tracks all memory
  • Task Manager displays Working Set and Memory profiler (on Windows) starts breakdown from Committed Memory
    • Tools like Process Explorer or VMMap can show you the real picture (on Windows)
  • Our goal atm is to surface this information to the tool so that we are consistent with OS tooling
    • It is quite challenging if we take into account all platforms

 

No. Everything the snapshot has information on is in the Tracked category. Wether that's Object associated or floating allocations or preallocated buffers. But the tree map only shows objects. You'll have to look that the Objects and Allocations page and choose the All Native Allocations Table or the Fragmention page. There is information for all of the 5.44GB of Tracked memory in the snapshot.

Unknown contains native plugin memory, IL2CPP Virtual Machine memory, etc as listed in the UI when you select it.

The other bar would be interesting to see in this context, the one with the Graphics & Graphics Driver category. E.g. I'm not certain how much that category is measured in the Task Manager, as that might not list dedicated VRAM usage? If you switch from Task Manager to Resource Monitor, that may become clearer too.

Also Executable and DLL may not fully count as working set. A can part of it be shared with other apps (Because that's what a dynamically linked library allows for) and it is likely not modified after loading from disk.