Can't upgrade from 400 fsb to 533 fsb CPU

your board gose too 2g a 3200 cpu with 400 fsb is the max you can go jim.

Specifications
CPU
• Supports Intel® P4 Northwood/Prescott/P4 Extreme Edition processors.(PCB v1.1 only)
• FSB 400(Northwood only)/533/800MHz
• Supports up 3.2GHz and higher speed
Memory Speed/CPU FSB Support Matrix
Memory Speed/CPU FSB Support Matrix

FSB\Memory clock DDR266 DDR333 DDR400 800 MHz YES YES* YES 533 MHz YES YES NO 400 MHz YES NO NO
• Intel® 865G Chipset
- Supports 800/533/400MHz Intel NetBurst micro-architecture bus.
- Integrated graphic controller.
- Supports PC2100/PC2700 /PC3200 memory.
- Supports AGP 8X/4X at 0.8V (AGP 3.0) or 4X at 1.5V (not support 3.3V) interface.
• Intel® ICH5 Chipset
- AC'97 2.3 interface
- 8 USB 2.0/1.1 ports
- 2 channel Ultra ATA/100 Bus Master IDE controller
- SMBus 2.0 support
- 2 serial ATA Host Controllers
- Integrated LAN controller
• Support 100(Northwood only)/133/200MHz
• Support 400(Northwood only)/533/800MHz Intel NetBurst micro-architecture bus.
• Supports two 64-bit wide DDR data channels.
• Available bandwidth up to 3.2GB/s(DDR 400) for single-channel
mode and 6.4GB/s(DDR 400) for dual-channel mode.
• Supports four unbuffered DIMM of 2.5 Volt DDR SDRAM.
• Supports up to 4GB memory size without ECC.
• One AGP slot supports 8x/4x at 0.8V (AGP 3.0) or 4x at 1.5V (3.3V is not supported).
• Three PCI 2.2 32-bit Master PCI Bus slots.
- Supports 3.3v/5v PCI bus Interface.
• One CNR slot
• Dual Ultra DMA 66/100 IDE controllers integrated in ICH5
- Supports PIO, Bus Master operation modes.
- Can connect up to four Ultra ATA drives.
• Serial ATA/150 controller integrated in ICH5
- Up to 150MB/sec transfer speeds.
- Can connect up to two Serial ATA drives.
• AC'97 link controller integrated in ICH5
• 6 channels software audio codec C-Media 9739A
- Compliance with AC97 v2.2 Spec.
- Meet PC2001 audio performance requirement.
- Can support SPDIF Out via 3-pin SPDIF bracket only.
• Intel 82562EZ
- Integrated 10/100 Ethernet MAC and PHY in one chip
- Supports 10Mb/s and 100Mb/s auto-negotiation operation
- Compliant with PCI v2.2, and LAN on Motherboard (LOM) standard

dit you try a bios update?Some motherboard needs a bios update for a newer cpu.

Your motherboard supports 2 different fsb's.
look these up @ cpu-world
you can use:
Intel Pentium 4 processor (478-pin)
- 533MHz system data bus - supports up to 2.8 GHz
- 400MHz system data bus - supports up to 2.4 GHz

Intel Celeron processor
- 400MHz system data bus - supports up to 2.0 GHz CPU speed
and here are the suppoted cpus:
Intel Celeron RK80531RC029128 BX80531P170G128 1.7 GHz 17 x 400 MHz, Willamette Any A RK80531RC033128 BX80531P180G128 1.8 GHz 18 x 400 MHz, Willamette Any A RK80531RC037128 BX80531P190G128 1.9 GHz 19 x 400 MHz, Willamette Any A RK80532RC041128 BX80532RC2000B 2.0 GHz 20 x 400 MHz, Northwood A 1.525V not supported RK80532RC045128 BX80532RC2100B 2.1 GHz 21 x 400 MHz, Northwood A 1.525V not supported Intel Pentium 4 RK80532PC021512 1.5 GHz 15 x 400 MHz, Northwood Any A RK80532PC025512 BX80532PC1600D 1.6 GHz 16 x 400 MHz, Northwood Any A RK80532PC029512 1.7 GHz 17 x 400 MHz, Northwood Any A RK80532PC033512 BX80532PC1800D 1.8 GHz 18 x 400 MHz, Northwood Any A RK80532PC037512 1.9 GHz 19 x 400 MHz, Northwood Any A RK80532PC041512 BX80532PC2000D 2.0 GHz 20 x 400 MHz, Northwood A 1.525V not supported 2.1 GHz 21 x 400 MHz, Northwood A 1.525V not supported RK80532PC049512 BX80532PC2200D 2.2 GHz 22 x 400 MHz, Northwood A 1.525V not supported RK80532PE051512 BX80532PE2266D 2.26 GHz 19 x 533 MHz, Northwood A 1.525V not supported RK80532PE056512 BX80532PE2400D 2.4 GHz 18 x 533 MHz, Northwood A 1.525V not supported RK80532PC056512 BX80532PC2400D 2.4 GHz 24 x 400 MHz, Northwood A 1.525V not supported RK80532PC060512 BX80532PC2500D 2.5 GHz 25 x 400 MHz, Northwood A 1.525V not supported RK80532PE061512 BX80532PE2533D 2.53 GHz 19 x 533 MHz, Northwood A 1.525V not supported RK80532PC064512 BX80532PC2600D 2.6 GHz 26 x 400 MHz, Northwood A 1.525V not supported RK80532PE067512 BX80532PE2667D 2.66 GHz 20 x 533 MHz, Northwood A 1.525V not supported RK80532PE072512 BX80532PE2800D 2.8 GHz 21 x 533 MHz, Northwood A 1.525V not supported

The Intel® 845G chipset is optimized for the Intel® Pentium® 4 processor supporting Hyper-Threading (HT) Technology†. It is designed with the high performance 533/400 MHz system bus and integrated high-speed USB 2.0.

Max Cpu
Pentium 4 2.8ghz with a 400mhz FSB and
Pentium 4 2.63ghz with a 533mhz fsb

pay close attention when getting your cpu if it has a 533 front side bus and is faster than 2.63 then the actual cpu speed will end up slower (you will see something like 2.1ghz) if it comes on due to multiplier limitations

well if the board support till 400FSb then the 533FSb CPU will not work with the board did you check the website and he board manual that says it support upto 533 bus?

CPU:
Supports Intel Pentium 4 Socket 478 processors with 800/533/400 MHz FSB
Supports Intel Hyper-Threading Technology Chipset: Intel 865PE / ICH5-R
Supports Dual Channel DDR 400 Memory
Supports Advanced Configuration and Power Management Interface (ACPI) Memory: Six 184-pin DIMM sockets
Supports Single/Dual Channel DDR 400 memory (Max. 4GB). Audio: High quality 6-channel AC'97 audio with S/P-DIF function with JAck Sensing IDE/SCSI: Dual Ultra DMA 66/100 IDE controllers integrated in ICH5R- up to four Ultra ATA drives
Serial ATA/150 controller integrated in ICH5R- Up to 150MB/sec transfer speeds
2 channels Serial ATA 150MB/s data transfer rate via Silicon Image PCI controller
GigaRAID IDE RAID Controller I/O Connectors: PS/2 Keyboard and mouse, 1 x Parallel, 2 x Serial, 4+4 x USB2.0, 1 x RJ45, 1 x Audio Expansion Slots: 1 x AGP (3.0) , 5 x PCI (2.3), 1 x DPS Additional Features: GIGABYTE Patented Technology Dual Power System 2 (DPS 2)
GIGABYTE Xpress3 Series Software
from the above configuration for the board you can see that it supports up to 4GB ddr max
hope this helps pls appreciate by rating as fixyaa

Hello there.

As per here , the largest cpu supported is the 1.4GHz Pentium 3.

Hope this helps.

P4S533-MX
The following table shows the support for CPU / Motherboard
CPU

Since PCB

Since BIOS

Note
Celeron 1.7 GHz (400 FSB, L2 cache:128KB) ALL
ALL

Celeron 1.8 GHz (400 FSB, L2 cache:128KB) ALL
ALL

Celeron 2.0 GHz (400 FSB, L2 cache:128KB) ALL
ALL

Celeron 2.1 GHz (400 FSB, L2 cache:128KB) ALL
ALL

Celeron 2.2 GHz (400 FSB, L2 cache:128KB) ALL
ALL

Celeron 2.3 GHz (400 FSB, L2 cache:128KB) ALL
1005

Celeron 2.4 GHz (400 FSB, L2 cache:128KB) ALL
1005

Celeron 2.5 GHz (400 FSB, L2 cache:128KB) ALL
1006

Celeron 2.6 GHz (400 FSB, L2 cache:128KB) ALL
1006

Celeron 2.7 GHz (400 FSB, L2 cache:128KB) ALL
1006

Celeron 2.8 GHz (400 FSB, L2 cache:128KB) ALL
1006

P4-1.4 GHz (Socket478, 400 FSB, L2 cache:256KB) ALL
ALL

P4-1.5 GHz (Socket478, 400 FSB, L2 cache:256KB) ALL
ALL

P4-1.6 GHz (Socket478, 400 FSB, L2 cache:256KB) ALL
ALL

P4-1.6A GHz (Socket478, 400 FSB, L2 cache:512KB) ALL
ALL

P4-1.7 GHz (Socket478, 400 FSB, L2 cache:256KB) ALL
ALL

P4-1.8 GHz (Socket478, 400 FSB, L2 cache:256KB) ALL
ALL

P4-1.8A GHz (Socket478, 400 FSB, L2 cache:512KB) ALL
ALL

P4-1.9 GHz (Socket478, 400 FSB, L2 cache:256KB) ALL
ALL

P4-2 GHz (Socket478, 400 FSB, L2 cache:256KB) ALL
ALL

P4-2.20 GHz (400 FSB, L2 cache:512KB) ALL
ALL

P4-2.26 GHz (533 FSB, L2 cache:512KB) ALL
ALL

P4-2.40 GHz (400 FSB, L2 cache:512KB) ALL
ALL
P4-2.40B GHz (533 FSB, L2 cache:512KB) ALL
ALL

P4-2.50 GHz (400 FSB, L2 cache:512KB) ALL
ALL

P4-2.53 GHz (533 FSB, L2 cache:512KB) ALL
ALL

P4-2.60 GHz (400 FSB, L2 cache:512KB) ALL
ALL

P4-2.66 GHz (533 FSB, L2 cache:512KB) ALL
ALL

P4-2.80 GHz (533 FSB, L2 cache:512KB) ALL
ALL

P4-2A GHz (Socket478, 400 FSB, L2 cache:512KB) ALL
ALL

P4-3.06 GHz (533 FSB, L2 cache:512KB, HT, C1/D1) ALL
ALL
Since PCB 2.0 or later support HT Function

You can go up to 3.0Ghz Pentium 533 Non Prescott. It has a 400/533 FSB