WARNING: This information is provided "as is" with no warranty. Use at your own risk!
This site is NOT affiliated with PB.

PB450 CPU Upgrade

Caution Only authorized service personnel should upgrade the system. Anyone who wants to upgrade the system herself/himself should know about the dangers of ESD (Electro-Static Discharge) and the necessary precautions. Unknowingly zapping the components of the computer will void the warranty.
CPU Installation

Note
The PB450 Motherboard DOES NOT support 3.3 volt CPU regardless the motherboard revision.

Component Locations
The upgrade processor installs in the Zero Insertion Force (ZIF) socket at location U50.

Upgrade Table
Any of the processors listed in the table below will work in the PB450 system. Set the jumpers accordingly.

  1. BIOS Upgrade ver 1.1a Required for P24 83 Mhz. .
  2. The Interposer is required for P24T upgrades on this motherboard
  3. Jumper J32 (Voltage Selection) is always on pins 3-5, 4-6.
  4. Revision D and G Motherboards do not have J29.

Jumpers J25 J29 J31
CPU Speed Multiplier SX/DX
486SX25 1-2 1-2 5-6
486SX33 2-3 1-2 5-6
486SX/2-50 1-2 2-3 5-6
486DX-33 2-3 1-2 1-2 & 3-4
486DX/2-50
486-25
486DX/4-75
P24T-62MHz
 1-2 2-3 1-2 & 3-4
486DX/2-66
ODP486-33
P24T-83MHz		 2-3 2-3 1-2 & 3-4
486DX/4-100
*486DX/4-120		 2-3 none 1-2 & 3-4

Jumper setting for J28 which is a 3 pin jumper. Jret-P24T or S-series reset control.
1-2 P24T or S-series CPU
2-3 Standard CPU

* Note
The DX4-120 CPU requires a 486 system, able to run at 40 MHz clock speed. None of our motherboards have been qualified to run at that speed. However, they will run at 33 MHz which will yield 100 MHz DX4 speed.
 
Purchase Referrals
End users should contact Intel at (800) 538-3373 for a referral to a dealer who handles Intel products.
 
Intel refers to the P24T as the Pentium OverDrive Processor or PODP5V.

Document Information