Pentium III 1266S vs Atom Z520

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.

Value Upgrade Path

This is the official ChipVERSUS Value Rating, comparing raw performance (PassMark) per dollar. Components placed above yours deliver better value for money. The Pentium III 1266S is positioned at rank 1140 and the Atom Z520 is on rank 523, so the Atom Z520 offers better cost-efficiency for playing games.

MSRP is the manufacturer's suggested retail price.•
Avg price is the current average price collected from markets across the web.

Performance Per Dollar Pentium III 1266S

#1

Ryzen 9 7950X

MSRP: $194|Avg: $20

546868%

#2

Core i9-10900T

MSRP: $120|Avg: $5

516737%

#3

Ryzen 3 PRO 4355GE

MSRP: $423|Avg: $5

375193%

#4

Ryzen Threadripper 3960X

MSRP: $1399|Avg: $85

113030%

#5

Ryzen 9 9950X

MSRP: $649|Avg: $129

89532%

#6

Ryzen 5 8400F

MSRP: $303|Avg: $55

78323%

#7

Ryzen 7 PRO 2700

MSRP: $299|Avg: $60

44860%

#8

Ryzen 5 2600X

MSRP: $229|Avg: $55

44274%

#9

Ryzen 3 PRO 5350G

MSRP: $150|Avg: $60

40312%

#10

Core Ultra 5 245KF

MSRP: $294|Avg: $189

40309%

#11

Ryzen 5 5500

MSRP: $159|Avg: $85

39858%

#12

Ryzen 5 3600

MSRP: $199|Avg: $80

38782%

#13

Core i3-9100E

MSRP: $202|Avg: $30

38240%

#14

Core Ultra 5 245K

MSRP: $319|Avg: $200

38086%

#15

Core i3-8300T

MSRP: $138|Avg: $25

37740%

#1140

Pentium III 1266S

MSRP: $369|Avg: $20

100%

#1141

Pentium 4 1.80

MSRP: $562|Avg: $40

70%

#1142

Pentium III 1133

MSRP: $990|Avg: $30

32%

Based on actual market prices and performance synthetic scores.

Performance Per Dollar Atom Z520

#167

Core Ultra 7 258V

MSRP: $450|Avg: $400

98%

#511

Atom x5-Z8300

MSRP: $20|Avg: N/A

682%

#512

Atom Z3735G

MSRP: $17|Avg: N/A

672%

#513

Core i5-480M

MSRP: $81|Avg: $77

617%

#514

Core i5-460M

MSRP: $80|Avg: $129

614%

#515

Core i5-2540M

MSRP: $266|Avg: $10

609%

#517

Core i5-450M

MSRP: $32|Avg: $31

588%

#518

Core i3-380M

MSRP: $49|Avg: $25

564%

#519

Core i5-430M

MSRP: N/A|Avg: $33

563%

#520

Core 2 Duo T6600

MSRP: N/A|Avg: $4

548%

#523

Atom Z520

MSRP: N/A|Avg: N/A

100%

Based on actual market prices and performance synthetic scores.

Performance Comparison

About PassMark

🏆 Chipversus Verdict

🚀 Performance Leadership

Generational Difference: This comparison involves processors from different technological eras. The Atom Z520 (2008) utilizes 45 nm technology and modern memory, providing a fundamental performance advantage.

Insight	Pentium III 1266S	Atom Z520
Gaming	✅ Superior gaming performance	❌ Lower gaming performance
Workstation	❌ Weaker in multi-core tasks	✅ Better multi-core power
Price	⚠️ Higher cost ($20)	✅ More affordable ($0)
Longevity	🛑 Legacy (Tualatin (2000−2002) / 130 nm)	🛑 Legacy (Silverthorne (2008−2010) / 45 nm)

💎 Value Proposition

The Pentium III 1266S (2001) relies on 130 nm technology and older memory, placing it in a different performance category relative to modern standards.

Insight	Pentium III 1266S	Atom Z520
Cost Efficiency	❌ Lower cost efficiency	❌ Lower cost efficiency
Upfront Cost	⚠️ Higher cost ($20)	✅ More affordable ($0)

Performance Check

Paired with RTX 4090

To accurately isolate CPU performance, all benchmarks below use an NVIDIA RTX 4090 as the reference GPU. This eliminates GPU-side bottlenecks and highlights pure processing throughput differences between the CPUs.

Note: Real-world results may vary based on your actual GPU. CPU performance impact is more visible in processing-intensive titles and high-refresh-rate gaming scenarios.

Pentium III 1266S Benchmark Check

Atom Z520 Benchmark Check

Technical Specifications

Side-by-side comparison of Pentium III 1266S and Atom Z520

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.

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.

⚡

Processing Power

The Pentium III 1266S packs 1 cores / 1 threads, matching the Atom Z520's 1 cores. Boost clocks reach 1.27 GHz on the Pentium III 1266S versus 0.03 GHz on the Atom Z520 — a 190.8% clock advantage for the Pentium III 1266S. The Pentium III 1266S uses the Tualatin (2000−2002) architecture (130 nm), while the Atom Z520 uses Silverthorne (2008−2010) (45 nm). In PassMark, the Pentium III 1266S scores 210 against the Atom Z520's 215 — a 2.4% lead for the Atom Z520. Both processors carry 0 kB of L3 cache.

Feature	Pentium III 1266S	Atom Z520
Cores / Threads	1 / 1	1 / 2
Boost Clock	1.27 GHz+4133%	0.03 GHz
Base Clock	—	1.33 GHz
L3 Cache	0 kB	0 kB
L2 Cache	512 kB	512 kB
Process	130 nm	45 nm-65%
Architecture	Tualatin (2000−2002)	Silverthorne (2008−2010)
PassMark	210	215+2%

🧠

Memory & Platform

The Pentium III 1266S uses the PGA370 socket (PCIe 1.1), while the Atom Z520 uses PBGA441 (PCIe 2.0) — making them incompatible on the same motherboard.