Atom Z520 vs Pentium III 1400S

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.

Atom Z520 vs Pentium III 1400S 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.

Atom Z520 vs Pentium III 1400S: Pros, Cons & Final Verdict

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

Atom Z520

2008

Why buy it

✅Draws 2W instead of 32W, a 30W reduction.

Trade-offs

❌Worse for gaming: lower average FPS than Pentium III 1400S across 27 shared CPU benchmark tests.
❌Lower PassMark (215 vs 228).
❌No boxed cooler included, unlike Pentium III 1400S.

Pentium III 1400S

2002

Why buy it

✅Better for gaming: +20.0% higher average FPS across 27 shared CPU benchmark tests.
✅Includes a boxed cooler (Yes), unlike Atom Z520.

Trade-offs

❌Launch MSRP is still $250 MSRP, while Atom Z520 mostly shows up through inconsistent older-market listings.
❌1500% higher power demand at 32W vs 2W.

Quick Answers

So, is Pentium III 1400S better than Atom Z520?

Yes. Pentium III 1400S is the better all-around CPU here. It gives you a 20.0% average FPS lead across 27 shared CPU game tests in our data and 6% better PassMark, which is enough to make it the stronger overall pick.

Which one is better for gaming?

If gaming is the priority, Pentium III 1400S is the better pick. According to our tests, it delivers 20.0% more average FPS across 27 shared CPU game tests.

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

For streaming, content creation, and heavier multitasking, Pentium III 1400S is the stronger fit. You are getting 6% better PassMark, backed by 1 cores and 1 threads.

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

Pentium III 1400S is the better buy right now. Pentium III 1400S comes in at an unclear MSRP at $250 MSRP versus unclear MSRP, and it still gives you a 20.0% average FPS lead across 27 shared CPU game tests in our data. It is also 100.0% better value on MSRP (0.9 vs 0.0 PassMark/$), so you are getting the faster CPU without taking a value hit on paper.

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

Atom Z520 makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2008 vs 2002). That makes it the safer long-term bet.

Atom Z520 vs Pentium III 1400S Technical Specifications

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

Atom Z520

The Atom Z520 is manufactured by Intel. It was released in 2 April 2008 (17 years ago). It is based on the Silverthorne (2008−2010) architecture. It features 1 cores and 2 threads. Base frequency is 1.33 GHz, with boost up to 0.03 GHz. L3 cache: 0 kB. L2 cache: 512 kB. Built on 45 nm process technology. Socket: PBGA441. Thermal design power (TDP): 2 Watt. Passmark benchmark score: 215 points. Launch price was $65.

Pentium III 1400S

The Pentium III 1400S 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: 512 kB. Built on 130 nm process technology. Socket: PGA370. Thermal design power (TDP): 32 Watt. Passmark benchmark score: 228 points. Launch price was $69.

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Processing Power

The Atom Z520 packs 1 cores / 2 threads, matching the Pentium III 1400S's 1 cores. Boost clocks reach 0.03 GHz on the Atom Z520 versus 1.4 GHz on the Pentium III 1400S — a 191.6% clock advantage for the Pentium III 1400S. The Atom Z520 uses the Silverthorne (2008−2010) architecture (45 nm), while the Pentium III 1400S uses Tualatin (2000−2002) (130 nm). In PassMark, the Atom Z520 scores 215 against the Pentium III 1400S's 228 — a 5.9% lead for the Pentium III 1400S. Both processors carry 0 kB of L3 cache.

Feature	Atom Z520	Pentium III 1400S
Cores / Threads	1 / 2	1 / 1
Boost Clock	0.03 GHz	1.4 GHz+4567%
Base Clock	1.33 GHz	—
L3 Cache	0 kB	0 kB
L2 Cache	512 kB	512 kB
Process	45 nm-65%	130 nm
Architecture	Silverthorne (2008−2010)	Tualatin (2000−2002)
PassMark	215	228+6%

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Memory & Platform

The Atom Z520 uses the PBGA441 socket (PCIe 2.0), while the Pentium III 1400S uses PGA370 (PCIe 1.1) — making them incompatible on the same motherboard. Maximum memory speed reaches DDR2-533 on the Atom Z520 versus PC133 on the Pentium III 1400S — the Atom Z520 supports 300.8% faster memory, which can translate to measurable gains in memory-sensitive workloads. The Pentium III 1400S supports up to 4 GB of RAM compared to 2 GB — 100% more capacity for professional workloads. Both feature 1-channel memory with ECC support. Both provide 0 PCIe lanes. Chipset compatibility: Intel US15W (Atom Z520) and Intel 815,VIA Apollo Pro 133T (Pentium III 1400S).

Feature	Atom Z520	Pentium III 1400S
Socket	PBGA441	PGA370
PCIe Generation	PCIe 2.0+82%	PCIe 1.1
Max RAM Speed	DDR2-533+301%	PC133
Max RAM Capacity	2 GB	4 GB+100%
RAM Channels	1	1
ECC Support	No	Yes
PCIe Lanes	0	0