Athlon XP 1800+
Pentium III 1266S
Athlon XP 1800+ vs Pentium III 1266S Performance Spectrum
About PassMark
PassMark CPU Mark evaluates processor speed through complex mathematical computations. It provides a reliable metric to compare multi-core performance, where higher scores indicate faster processing for multitasking, gaming, and heavy workloads.
Athlon XP 1800+ vs Pentium III 1266S FPS Benchmarks
Predicted gaming performance across popular games. Tested paired with GeForce RTX 5090 to isolate CPU performance.
Search any supported game below to compare 1080p FPS for both components.
Path of Exile 2
Counter-Strike 2
League of Legends
Valorant
Among Us
Apex Legends
ARC Raiders
Baldur's Gate 3
Call of Duty: Black Ops 6
Athlon XP 1800+ vs Pentium III 1266S: Pros, Cons & Final Verdict
See where each CPU makes more sense in practice: gaming, heavier work, platform cost, power draw, and upgrade path.
Athlon XP 1800+
2001Why buy it
- ✅Better for gaming: +20.0% higher average FPS across 50 shared CPU benchmark tests.
- ✅Costs $117 less on MSRP ($252 MSRP vs $369 MSRP).
- ✅Delivers 56.9% more PassMark for each dollar spent, at 0.9 vs 0.6 PassMark/$ ($252 MSRP vs $369 MSRP).
- ✅Includes a boxed cooler (Stock), unlike Pentium III 1266S.
Trade-offs
- ❌120% higher power demand at 66W vs 30W.
Pentium III 1266S
2001Why buy it
- ✅Draws 30W instead of 66W, a 36W reduction.
Trade-offs
- ❌Worse for gaming: lower average FPS than Athlon XP 1800+ across 50 shared CPU benchmark tests.
- ❌Lower PassMark (210 vs 225).
- ❌Lower PassMark per dollar, at 0.6 vs 0.9 PassMark/$ ($369 MSRP vs $252 MSRP).
- ❌No boxed cooler included, unlike Athlon XP 1800+.
Quick Answers
So, is Athlon XP 1800+ better than Pentium III 1266S?
Which one is better for gaming?
Which one is better for streaming, content creation, and heavy multitasking?
Which one is the smarter buy today, not just the cheaper CPU?
Which one is more future-proof for 2026 and beyond?
Athlon XP 1800+ vs Pentium III 1266S Technical Specifications
Side-by-side specs, architecture details, clocks, memory, power, and platform differences.
Athlon XP 1800+
The Athlon XP 1800+ is manufactured by AMD. It was released in Janeiro 2001 (24 years ago). It is based on the Thoroughbred (2001−2002) architecture. It features 1 cores and 1 threads. Max frequency: 1.53 GHz. L3 cache: 0 kB. L2 cache: 256 kB. Built on 180 nm process technology. Socket: A. Thermal design power (TDP): 66 Watt. Passmark benchmark score: 225 points. Launch price was $59.
Pentium III 1266S
The Pentium III 1266S is manufactured by Intel. It was released in 2007-01-01. It is based on the Tualatin (2000−2002) architecture. It features 1 cores and 1 threads. Max frequency: 1.27 GHz. L3 cache: 0 kB. L2 cache: 512 kB. Built on 130 nm process technology. Socket: PGA370. Thermal design power (TDP): 30 Watt. Passmark benchmark score: 210 points. Launch price was $69.
Processing Power
Both the Athlon XP 1800+ and Pentium III 1266S share an identical 1-core/1-thread configuration. Boost clocks reach 1.53 GHz on the Athlon XP 1800+ versus 1.27 GHz on the Pentium III 1266S — a 18.6% clock advantage for the Athlon XP 1800+. The Athlon XP 1800+ uses the Thoroughbred (2001−2002) architecture (180 nm), while the Pentium III 1266S uses Tualatin (2000−2002) (130 nm). In PassMark, the Athlon XP 1800+ scores 225 against the Pentium III 1266S's 210 — a 6.9% lead for the Athlon XP 1800+. Both processors carry 0 kB of L3 cache.
| Feature | Athlon XP 1800+ | Pentium III 1266S |
|---|---|---|
| Cores / Threads | 1 / 1 | 1 / 1 |
| Boost Clock | 1.53 GHz+20% | 1.27 GHz |
| L3 Cache | 0 kB | 0 kB |
| L2 Cache | 256 kB | 512 kB+100% |
| Process | 180 nm | 130 nm-28% |
| Architecture | Thoroughbred (2001−2002) | Tualatin (2000−2002) |
| PassMark | 225+7% | 210 |
| Geekbench 6 Single | 180 | — |
| Geekbench 6 Multi | 651 | — |
Memory & Platform
The Athlon XP 1800+ uses the A socket (PCIe 1.1), while the Pentium III 1266S uses PGA370 (PCIe 1.1) — making them incompatible on the same motherboard.
| Feature | Athlon XP 1800+ | Pentium III 1266S |
|---|---|---|
| Socket | A | PGA370 |
| PCIe Generation | PCIe 1.1 | PCIe 1.1 |
| Max RAM Speed | DDR1 | — |
| Max RAM Capacity | 2 GB | — |
| RAM Channels | 1 | — |
| ECC Support | No | — |
Advanced Features
Virtualization: No (Athlon XP 1800+) / not specified (Pentium III 1266S). Primary use case: Athlon XP 1800+ targets Budget. Direct competitor: Athlon XP 1800+ rivals Pentium D 830.
| Feature | Athlon XP 1800+ | Pentium III 1266S |
|---|---|---|
| Integrated GPU | No | — |
| Unlocked | No | — |
| AVX-512 | No | — |
| Virtualization | No | — |
| Target Use | Budget | — |
Value Analysis
At launch, the Athlon XP 1800+ was priced at $252, while the Pentium III 1266S came in at $369. On launch pricing ($252 vs $369), Athlon XP 1800+ was $117 cheaper. In terms of value on MSRP (PassMark points per dollar), the Athlon XP 1800+ delivers 0.9 pts/$ vs 0.6 pts/$ for the Pentium III 1266S — making the Athlon XP 1800+ the 44.3% better value option.
| Feature | Athlon XP 1800+ | Pentium III 1266S |
|---|---|---|
| MSRP | $252-32% | $369 |
| Performance per Dollar | 0.9+50% | 0.6 |
| Release Date | 2001 | 2001 |
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