iMacG5: memory bus, how to detect it, a new trial

if you enter the following command line:
ioreg -p IODeviceTree -n memory -S | grep "ram-layout-architecture"
it will return 00000001 for an iMacG5 with 2 identical DDR modules, and it is also true on a PowerMac G5, but it will return 00000002 when executed on a iMacG5 sporting a single DDR module. If some iMacG5 users whish to test this command line we will quickly know if it is a way to determine if you memory bus is running on 64 or 128bits.