The Intel® Core™ i5-2xxx Desktop Processors use a chipset based on the Intel® 6 Series Express Chipsets, while the Intel® Core™ i5-3xxx Desktop Processors use a chipset based on the Intel® 7 Series Express Chipsets. These processors are backward and forward compatible with some notable exceptions.
Check with the manufacturer of the desktop board you are using to see if it supports the processor you want to use and the recommended update process.
If you are installing an Intel® Core™ i5-3xxx Processor on a desktop board based on the Intel® 6 Series Express Chipset, it might require updated BIOS, ME8 firmware, and drivers.
This document shows the update process for Intel® Desktop Boards based on the Intel® 6 Series Express Chipset: Updating the BIOS on Intel® Desktop Boards with Intel® 6 Series Express Chipsets.