by Bubba "Masterfung" Wolford

Test System

• Intel Pentium III 550 MHz CPU
• Abit BX6 Revision2 Motherboard
• 256 MB PC133 RAM
• 2 Western Digital 18.0 GB 7200 RPM Expert drives
• 3dfx Voodoo 3 3000 166MHz video card
• Kenwood True 52X Multibeam CDROM
• Diamond MX300 sound card
• 3Com 3C905B 10/100 Ethernet NIC
• Viewsonic 21" G810-2
• Inwin medium tower w/300 watt power supply
• Windows 98 Second Edition (SE)

Background: CPU Primer

One of the most common questions I get asked about CPU's is the difference between a Pentium II and Pentium III CPU. So let's review the differences between Intel Celeron, Pentium II and Pentium III.

Intel Celeron

When the initial Celeron "Deschutes" chips were released (233-300 MHz), they were supposed to compete against the AMD K6-2 CPUs. Running on a Pentium II core, the new chip seemed a sure winner. They suffered from one major flaw, however: Intel did not include any cache on the CPU. Who would want a cacheless CPU?

No one, really. While competing against AMD, however, the performance of the original Celeron chips is still quite strong. While the initial Intel Celeron had no cache, the AMD K6-2 cache (128K) is limited to the computer's bus speed, thus negating any real advantage.

A virtual tie in performance compared to AMD was not what Intel had in mind. They wanted to handily beat AMD in the low-end market and when word spread that the initial CPU's were cacheless, Intel sought to fix the problem once and for all.

When Intel introduced the 300a "Mendocino" Celeron, they never fathomed what a huge hit this CPU would become. As opposed to the original, the 300A core added 128K of cache. Unlike the AMD K6-2 cache, which runs at the motherboard's bus speed, this new Celeron's 128K-cache runs at the full speed of the CPU!

Click to continue

300A to 450MHz

Better still, thousands of Intel users across the world found that they could overclock their 300 MHz CPU on motherboards which allow the user to adjust voltages and bus speeds. How much, you ask? All the way to 450 MHz, 464 MHz and even in some cases 504 MHz!

But there was one trick. Only the Malaysian 300a CPU was guaranteed to make the jump from 300 MHz to 450 MHz. These were also the only CPUs that could make the jump from 300 MHz to 464 or 504 MHz. The Costa Rica production 300a only had about a 50% chance of moving from 300 to 450 MHz, and then only when increased to 2.1 or 2.2 volts, causing it to run very hot.

Personally, I have helped build about 15-20 Celeron 300a computers. Some had Malaysia chips and some had Costa Rica CPUs. Every single Celeron 300a from Malaysia could hit 464 MHz with only a .05 increase in voltage. Since the cache was running the same speed as the CPU, the combination of overclocking, full speed cache and low price made the 300a a very hot commodity.

From Slot 1 to Socket 370

Intel has since introduced a PPGA socket 370 Celeron that besides being socketed like the old Pentium and AMD CPUs, is identical in performance to the slot 1 Celeron. Since the huge acceptance that the 300a Celeron experienced, Intel has not altered the chemistry, which brought Celeron from the bastard child CPU to one that is the gamers choice CPU in the quest for best performance/price ratio.

Comparing an AMD K6-2 or K6-3 versus Celeron has now become a no win situation for AMD. Celeron retaining the Pentium II core, with full speed cache and overclocking capability is a truly awesome CPU.

The Intel Celeron tradition continues today. The latest Celeron is running at 500 MHz. It is still running on a 66 MHz bus with 128K cache. Once the Camino chipset (4X AGP) and Coppermine are introduced in a few weeks, we will see a Coppermine Celeron CPU running a 600 MHz with a 100 MHz bus.

Go to Part II