AMD Athlon, Athlon XP
The first Slot A Athlons perform well compared to Pentium II, Pentium III Katmai or lower Celeron variants. Not so well when it comes to PIII Coppermine however. The biggest disadvantage seems to be the slow on-SECC cache. While the K7 core has no problem operating at 1 GHz, the cache tops out at 300 - 350 MHz. In memory intensive applications and games Athlons 600 - 900 MHz are almost equal. Quake 3 Arena demonstrates this behavior - Athlon 600 scores 81.7 fps and Athlon 900 scores 83.6 fps. Looking at Intel scores, it is obvious how bad this performance increase is. For example PIII 600 can do 78.6 fps, but PIII 866 moves the fps counter to 102.4 fps. Other than slow cache, bad Slot A chipsets also can be blamed for sub-optimal performance.
Thunderbird Athlons are doing much better. The on-die L2 cache really helps to raise the performance to expected level - which means equal to PIII at the same clock. Chipsets for Socket 462 are also much more mature and faster - VIA KT133A is the best S462 chipset of this era. But the chipset alone is not enough - good motherboard design and BIOS is also important. The difference between good and bad board can be as much as 10%. The greatest weakness of Thunderbird (as well as the original Athlon) is power consumption. According to the measured figures the first generation K7 performance/watt effectivity tops out around 700 MHz. When pushing the frequency above, the amount of power and heat rises fast. At 1 GHz, Thunderbird consumes 60 W, while Pentium III Coppermine only 29 W.
Athlon XP Palomino is not much faster than Thunderbird at the same clock. On the other hand it can operate at frequency by hundreds of MHz faster. Also power efficiency is greatly improved, so in the end it is significantly better processor than Thunderbird. It is worth mentioning the AXP supports SSE instruction set, which allows it to run even relatively modern applications.
Dual CPU rigs based on the AMD 760MPX chipset feel somewhat inconsistent. In case of single-threaded applications, pair of AXP 1600+ is steadily slower than single 1600+ running VIA KT266A chipset. The greatest loss can be seen in games. IN the performance summary figures AMD 2-way SMP shows performance increase of 21%. Intel is better at this with perfomance uplift of 30% (PIII 1000EB -> 2× PIII Xeon 1000).
Intel Pentium III
Pentium III performance is consistent in the whole range of tests. The strongest fild for PIII is file compression in Winrar, photo edit and games. Rendering in POV-Ray and synthetic benchmarks on the other hand feel slower. Back in the day energy efficiency wasn't something to look at. Today however it is a big deal. When looking at PIII this way, all Coppermine variants are very good and beat all Athlons Classic and Thunderbird. Tualatin takes this another step higher, running with 60-70% better performance/watt than Coppermine. Of course the new 130 nm process is responsible for this, and to some extent also the Asus TUSL2 - which for unknown reason supplied only 1.3V instead of standard 1.45V.
Intel Pentium 4
The NetBurst architecture was developed with high frequency and memory bandwidth in mind. Frequency is not the problem for P4 Willamette - at the end of year 2000 P4 reached 1.5 Ghz and in 2001 up to 2 GHz. Fast enough memory is where it gets more difficult. RDRAM (800 MHz, 32-bit – 3.2 GB/s) is defnitely a good match and also was very expensive at the time. DDR (333 MHz, 64-bit – 2.7 GB/s) is also good, but there werent many good boards. SDRAM (133 MHz, 64-bit – 1 GB/s) certainly is not suitable. Pentium 4 1.5 with SDRAM is slower in pretty much all tasks. Most of all in games (18% slower) and file compression (24% slower).
Even when using the best possible components for P4, it still is somewhat disappointing, the raw performance is simply too low. The Willamette core is not exactly power efficient, perf/watt is worse than PIII Coppermine, but still better than all Athlons except AXP 1600+.
VIA processors are intended as a cheap alternative to AMD or Intel for office use. C3 is in fact only slightly improved and faster clocked IDT Winchip made using more advanced process. Although the tested C3 operates at 800 MHz, simple in-order architecture and FPU unit running at half clock can't compete with Intel and AMD processors. Not even units few years older. In most tests the C3 ended up last, on average 35% behind the Pentium II 450.