For sale is a rare FastMac 1.4GHz G4 processor upgrade module (5B-1400CP) for the Apple Power Mac G4 Cube. This listing includes the heavy copper heatsink designed for Cube installation.

This upgrade has been tested in a Power Mac G4 Cube and confirmed working at 1.4GHz.

System requirements: Mac OS 9.2.1 or later and appropriate firmware updates may be required depending on system configuration.


Fast and careful shipping from Tokyo, Japan.
Please be aware of any customs import duties or taxes in your country. 

🇺🇸 US buyers: shipments are sent DDP (Delivered Duty Paid), which means there are no duty fees on delivery, as duties are included in the shipping rate.

Please also note that customs delays may occur, particularly within the EU.

This is vintage hardware/software for vintage computers. Use of this item requires era-appropriate knowledge and compatible hardware/software. Please carefully verify your intended use and compatibility before purchasing. I am happy to answer reasonable questions, but compatibility with every system or configuration cannot be guaranteed, and step-by-step installation support is not provided. Issues arising from incorrect installation, modification, or incompatible use are outside the seller’s responsibility.

I usually ship within 24 hours. If shipping falls on a Saturday in Japan, dispatch may occur the following Monday.