Your Power Mac G5 uses a PowerPC 970MP (G5) CPU which is based on the RISC architecture. The Intel CPUs (Core2Duo, i3. i5 & i7) are CISC based architecture. The OS’s are very different! Your system can only support the older Mac OS-X. The early OS-X OS’s where in fact dual binary! So the RISC code would be loaded on your system and if you had an Intel system the CISC code would load in! It was very novel in its day.
Here’s an interesting nugget! The A chips used in the iPhone & iPad’s are RISC based! And iOS is a branch off of the RISC OS-X code stream.
So what to do here?
If your system is working tinker around with it. Just don’t get online with it as your system is not secure from all of the malware, trojans and viruses that are now floating out there in the wild.
If the system is not working or you want to get more out of it, then maybe you might strip the case down and install an Intel based logic board - Hackintosh within a Power Mac! Retro Power Mac G5 Hackintosh & Power Mac G5 Conversion
For reference: Power Macintosh G5 "Quad Core"