My overclocking experience with the P2-450 was less than stellar. When I first got the system I spent a couple days trying to overclock it, but was unsuccessful. I managed to get it running at 504MHz for a brief moment on a few occasions but the system would inevitably lock up.

The P3-550E was a different story. With the BH6 motherboard making it's debut during the overclocking frenzy that appeared with Intel's Celeron 300a processor, Abit made sure there were plenty of options to tweak BIOS settings in their SoftMenu technology. The user-defined mode allows a variety of settings to be configured such as the external clock speed, CPU multiplier, AGP bus speed, and voltage.

H. Oda's WCPUID Utility

Because the CPU clock speed multiplier is locked, I had to resort to increasing the external clock speed. By overclocking the motherboard bus speed, you are effectively overclocking PCI devices. On a standard BX board, PCI devices are designed to run at 33MHz (100MHz/3) and overclocking to a bus speed of 112MHz causes PCI devices to run at 37.5MHz (112MHz/3). Newer motherboards allow the PCI divisor to be changed to 4 to support a 133MHz bus speed (133MHz/4=33MHz).

Abit BH6 - External Clock (PCI) Settings

I been running fine at a 124MHz bus speed (and 5.5 clock multiplier), which bumps up the CPU to 683MHz. The next highest BIOS setting was a 133HMz bus speed which was a no go. Unfortunately (for me), the system locked up and data on the hard drive was corrupted. I had no choice other than to re-install Windows 98. Maybe getting an overclocking friendly hard drive or PC133 rated memory would help, but I'm tickled pink running at 683MHz.

Ok, let's put a hurtin' on Quake 3 - or is it the other way around?

The benchmark settings:

• P2-450MHz - running at 450MHz - Annihilator Pro (GeForce DDR) at default clock speeds (120MHz core/300MHz memory)



• P3-550E - running at 550MHz, 616MHz, and 683MHz - Annihilator Pro at 120MHz/300MHz and 145MHz/345MHz



• Abit BH6 440BX motherboard - BIOS version NV



• 128MB Hitachi PC100 SDRAM



• Seagate Medalist Pro - 7200RPM - 6.4GB



• NVIDIA Detonator drivers - version 3.68



• Quake 3 Arena - version 1.16n



• VSYNC and sound disabled

Quake 3 - High Quality Settings - Demo001

32-Bit Color / 32-Bit Textures

Frames Per Second

At lower resolutions, the P3-P550E provides much more horsepower to the GeForce than the P2-450 and as a result, performance improves significantly at resolutions of 640x480 (93.0 vs 70.4) and 800x600 (84.6 vs 68.4).

At 1024x768 and above, the fill rate of the GeForce becomes a factor as the difference in performance of the P3-550E over the P2-450 isn't as great.

You can certainly see the effects of overclocking, as the P3-550E running at 683MHz and Annihilator Pro overclocked to 145MHz/345MHz manages to get over 70fps at 1024x768!

Over 70 FPS - 1024x768 w/High Quality Settings!

Next Page: 3DMark2000 Benchmarks