This seems to explain things pretty clearly.
|Definition||Task Manager||Process Explorer||vadump -s|
|Physical memory in use||Mem Usage||Working Set||WorkingSetSize|
|Private (no DLL) VM allocated/committed||VM Size||Private Bytes||PagefileUsage|
|Total VM (including mmap, dll, etc)||N/A||Virtual Size||(Image + Priv + Mapped) Commitment + Dynamic Reserved Memory|
On 32-bit Windows, max address space (virtual size) is 2GB.
The 3 types of commitment in vadump -s are:
- Image: process executable code
- Mapped: memory mapped stuff like files
- Private: process heap (and stack?)
vadump -so has a section that breaks down working set. Two entries are important: Heap is Windows native heap, and Other Data would be, e.g. CLR and JVM stuff.