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AMD Athlon XP vs Pentium 4 Take 2

Posted: April 3rd, 2002
Written by: Tuan Huynh

Brief Overview

Before I go on comparing the two processors, Iíll take some time to give a brief recap on the Pentium 4 Northwood and Athlon XP (Palomino).

As you may recall, the Athlon XP based on the Palomino architecture was launched around October, shortly after the launch of Microsoftís Windows XP. With the launch of the Athlon XP, AMD also introduced their modeling system, which they claimed is how fast the Athlon XP would perform compared to the previous Thunderbird core.

The Athlon XP also sported a few enhancements compared to its Thunderbird based predecessors. AMD called the enhancements itís ďQuantispeed Architecture.Ē Quantispeed architecture was nothing more then a fancy name for AMDís enhancements, such as their advanced TLB buffers, improved data pre-fetch, and 3D Now professional, which was nothing more then 3D Now + SSE instructions.

While the Athlon XP (Palomino) saw small improvements over the Thunderbird, this allowed the Athlon XP to outperform the Pentium 4ís based on the Willamette core. Intel of course, didnít let AMD enjoy the limelight for that long. In January, we saw Intel launch their Pentium 4ís based on their new Northwood core.

The Northwood Pentium 4ís received much needed improvements. These improvements included a die shrink to 0.13u, which allowed the processor to run much cooler and scale up to higher speeds. Along with the die shrink Intel also doubled the L2 cache from 256kb to 512kb. When the Northwood was launched, we saw a tight race between the Athlon XP and Pentium 4 Northwood, with both processors barely outperforming one another.

Features Comparison


P4 2.4 GHz (Northwood)

Athlon XP2100+ (Palomino)

Clock Speed

2.4 GHz





Pin Count



Fabrication Process



L1 Cache



L2 Cache

512kb Full speed

256kb Full Speed

L2 Cache Data Path



Front Side Bus

400 MHz (100 MHz QDR)

266 MHz (133 MHz DDR)

Memory Types Supported



SIMD Instructions


3D Now Pro, SSE, MMX


Approximately $650


Looking at the chart specifications comparison, we see that the Pentium 4 holds a 667 MHz clock over the Athlon XP, while AMD has proven to us that clock speed doesnít translate into performance, weíll have to wait and see ;).

With the introduction of the Classic Slot A Athlonís we saw that AMDís 128kb L1 cache had a greater hit ratio which allowed it to outperform the Katmai P3ís. In terms of L1 cache, the Pentium 4 has an eighth the L1 cache the Athlon has, but in exchange, the Pentium 4 has twice the amount of L2 cache as the Athlon XP. The cache on the Athlon XP totals to 384kb, while the total cache on the Pentium 4 is 520kb. Letís just take a quick little recap; the more cache a processor has, the faster a processor will perform since greater cache will have a greater hit ratio, which would make the processor have to access the RAM less. While you can have an unlimited amount of L2 cache, it would be useless unless the data throughput between the processor and the L2 cache is wide enough to support the cache. The Pentium 4 has plenty of bandwidth the processor and L2 (256bits) compared to the Athlon XPís.

While the Pentium 4 uses the Net burst architecture, has a 100 MHz FSB, which when used effectively is 400 MHz compared to the Athlon XPís 133 MHz, which is 266 MHz effectively. This allows the Pentium 4ís to have a lot of bandwidth which would be most effective in multimedia production.

When Intel launched the Pentium 3, we saw the introduction of SSE, which was much like MMX but provided increased performance enhancements that more software developers took advantage of. When Intel released the Pentium 4, they introduced a newer and improved version of SSE called SSE2. When applications were optimized for SSE2, we saw the Pentium 4ís performance improve drastically. With the introduction of the Athlon XP, we finally saw the inclusion of SSE on non-Intel processors; this allowed AMD to finally catch up to the Pentium 4 in SSE optimized benchmarks such as Sysmark Internet Content Creation.

As for price, the Athlon XP holds a significant advantage over the Pentium 4, as the Athlon XP only costs $241 (as found on Price watch) compared to the Pentium 4ís estimated $650 price mark. This will definitely make the Athlon XP2100+ more attractive price wise.

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