Downloading PPCchecker 2.6 for Mac from our website was free. PPCchecker for Mac relates to System Tools.
From the developer:
PPC Checker is a small utility written by Michiro Isobe that will report whether your G3 CPU is Copper or Aluminum based and reports the CPU revision for both G3 and G4 CPUs. PPC Checker will also report if your G3 has a 10x bus/cpu ratio capability. (A plus for older Macs with lower bus speeds.)