Pentium III 1266S vs Pentium III 1400

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.

Pentium III 1266S vs Pentium III 1400 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.

Pentium III 1266S vs Pentium III 1400: Pros, Cons & Final Verdict

See where each CPU makes more sense in practice: gaming, heavier work, platform cost, power draw, and upgrade path.

Pentium III 1266S

2001

Why buy it

Trade-offs

❌Worse for gaming: lower average FPS than Pentium III 1400 across 50 shared CPU benchmark tests.
❌Lower PassMark (210 vs 228).
❌Lower PassMark per dollar, at 0.6 vs 0.9 PassMark/$ ($369 MSRP vs $250 MSRP).

Pentium III 1400

2001

Why buy it

✅Better for gaming: +20.0% higher average FPS across 50 shared CPU benchmark tests.
✅Costs $119 less on MSRP ($250 MSRP vs $369 MSRP).
✅Delivers 60.3% more PassMark for each dollar spent, at 0.9 vs 0.6 PassMark/$ ($250 MSRP vs $369 MSRP).

Trade-offs

❌Fewer obvious downsides in this matchup outside of normal market pricing swings.

Quick Answers

So, is Pentium III 1400 better than Pentium III 1266S?

Yes. Pentium III 1400 is the better all-around CPU here. It gives you a 20.0% average FPS lead across 50 shared CPU game tests in our data, 8.6% better PassMark, and the stronger long-term platform, which is enough to make it the stronger overall pick.

Which one is better for gaming?

If gaming is the priority, Pentium III 1400 is the better pick. According to our tests, it delivers 20.0% more average FPS across 50 shared CPU game tests.

Which one is better for streaming, content creation, and heavy multitasking?

For streaming, content creation, and heavier multitasking, Pentium III 1400 is the stronger fit. You are getting 8.6% better PassMark, backed by 1 cores and 1 threads.

Which one is the smarter buy today, not just the cheaper CPU?

Pentium III 1400 is the better buy right now. Pentium III 1400 comes in $119 cheaper on MSRP at $250 MSRP versus $369 MSRP, and it still gives you a 20.0% average FPS lead across 50 shared CPU game tests in our data. It is also 60.3% better value on MSRP (0.9 vs 0.6 PassMark/$), so you are getting the faster CPU without taking a value hit on paper.

Which one is more future-proof for 2026 and beyond?

Pentium III 1400 makes more sense long term for 2026 and beyond. You are getting more multi-core headroom with 1 cores / 1 threads instead of 1/1. That extra compute headroom is more likely to matter as games, background tasks, and creator workloads get heavier.

Pentium III 1266S vs Pentium III 1400 Technical Specifications

Side-by-side specs, architecture details, clocks, memory, power, and platform differences.

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.

Pentium III 1400

The Pentium III 1400 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: 1.4 GHz. L3 cache: 0 kB. L2 cache: 256 kB. Built on 130 nm process technology. Socket: PGA370. Thermal design power (TDP): 31 Watt. Passmark benchmark score: 228 points. Launch price was $69.

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Processing Power

Both the Pentium III 1266S and Pentium III 1400 share an identical 1-core/1-thread configuration. Boost clocks reach 1.27 GHz on the Pentium III 1266S versus 1.4 GHz on the Pentium III 1400 — a 9.7% clock advantage for the Pentium III 1400. Both are built on the Tualatin (2000−2002) architecture using a 130 nm process. In PassMark, the Pentium III 1266S scores 210 against the Pentium III 1400's 228 — a 8.2% lead for the Pentium III 1400. Both processors carry 0 kB of L3 cache.

Feature	Pentium III 1266S	Pentium III 1400
Cores / Threads	1 / 1	1 / 1
Boost Clock	1.27 GHz	1.4 GHz+10%
L3 Cache	0 kB	0 kB
L2 Cache	512 kB+100%	256 kB
Process	130 nm	130 nm
Architecture	Tualatin (2000−2002)	Tualatin (2000−2002)
PassMark	210	228+9%

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Memory & Platform

Both processors use the PGA370 socket with PCIe 1.1.

Feature	Pentium III 1266S	Pentium III 1400
Socket	PGA370	PGA370
PCIe Generation	PCIe 1.1	PCIe 1.1

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Value Analysis

At launch, the Pentium III 1266S was priced at $369, while the Pentium III 1400 came in at $250. On launch pricing ($369 vs $250), Pentium III 1400 was $119 cheaper. In terms of value on MSRP (PassMark points per dollar), the Pentium III 1266S delivers 0.6 pts/$ vs 0.9 pts/$ for the Pentium III 1400 — making the Pentium III 1400 the 46.3% better value option.

Feature	Pentium III 1266S	Pentium III 1400
MSRP	$369	$250-32%
Performance per Dollar	0.6	0.9+50%
Release Date	2001	2001

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