3 Things to Know About the iBook G3 Clamshell's Soldered CPU and GPU
Both the PowerPC G3 processor and ATI Rage Mobility graphics chip are soldered to the logic board. This means you cannot upgrade either component — the machine stays exactly as configured at the factory.
Soldering the CPU and GPU was standard practice for Apple’s portable line at the time. It was not a design flaw, just how laptops were built in that era.
You would not want to push the ATI Rage Mobility any harder than it already gets. The graphics chip is already underpowered by modern standards, so upgrading it would not be worthwhile.