Replacing the Pentium Pro processor - PC Server 325, 330

Resolving The Problem

Before replacing, upgrading, or adding an additional Pentium Pro Processor in the IBM PC Server 325 (Type 8639) and PC Server 330 (Type 8640), it is important to verify that Server has the latest BIOS level.

Use the following procedure BEFORE replacing, upgrading or adding an additional Pentium Pro processor:

1. Perform a shutdown of the operating system and then reboot.

2. When the IBM logo screen appears, check the BUILD ID in the lower left hand corner of the screen. An example of a BUILD ID is RAET29AUS. The 29A is the BIOS level. Compare this level with the latest BIOS level on the Database

3. If the system BIOS level is at a lower level (lower numeric value) than the latest BIOS level available on the database, download the latest BIOS image and update the system BIOS prior to installing the processor.

The Intel Pentium Pro processor has an area to store microcode patches. This microcode is stored in the BIOS of the PC Server 325/330 and is loaded into the Pentium Pro during POST. Each Pentium Pro processor has a stepping level. Each stepping level requires a specific microcode patch. The latest level BIOS will contain all the microcode patches for all processor stepping levels.
When the Server POSTs, a specific microcode is loaded to the Pentium Pro processor depending on its stepping level. If the BIOS is downlevel, the processor may not receive the correct microcode because it is not present in the downlevel BIOS. The processor will not operate properly without the correct microcode patch.