lstopo - display a topological map of a system

The hwloc (hardware locality) package contains the useful tool lstopo. To install use:

sudo apt-get install hwloc

By default, lstopo will display a logical view of the system caches and CPU cores, for example:

To get a non-graphical output use:

lstopo -

Machine (1820MB) + Socket #0 + L3 #0 (3072KB)
  L2 #0 (256KB) + L1 #0 (32KB) + Core #0
    PU #0 (phys=0)
    PU #1 (phys=2)
  L2 #1 (256KB) + L1 #1 (32KB) + Core #1
    PU #2 (phys=1)
    PU #3 (phys=3)

lstopo is also able to output the toplogy image in a variety of formats (Xfig, PDF, Postscript, PNG, SVG and XML) by specifying the output filename and extension, e.g.

lstopo topology.pdf

For more information, consult the manual for hwloc and lstopo.