The main chipset is reportedly absolutely identical. The only difference between the one in Apple's computer and in the Perseverance rover which is currently exploring space is the versions of the processor. In a probe, the processor can withstand temperatures ranging from -55 to 125 degrees Celsius and its price is $200,000.
The iMac G3 used the PowerPC 750, which at one time was way ahead of its competitors in terms of performance. It based on a 32-bit architecture and had a single core clocked at 233 MHz with 6 million transistors.
Intil Apple switched to Intel in 2005, it used PowerPC chips in the iMac. The tech giant is now undergoing changes of a similar kind, moving away from Intel processors and implementing its own ARM processors into its devices.