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.
Intel recommends that you check with the manufacturer of the desktop board you are using to see if it supports the processor you want to use.
If you are installing an Intel® Core™ i5-3xxx Processor into a desktop board based on the Intel® 6 Express Series Chipset, you may need an updated BIOS, ME8 firmware, and drivers. Always check with your desktop board manufacturer for supported processors and the recommended update process.
Here is a document that 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