
Phenom II X2 B55

Ryzen 9 5900X
Performance Spectrum - CPU
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.
Value Upgrade Path
This is the official ChipVERSUS Value Rating, comparing raw performance (PassMark) per dollar. The Phenom II X2 B55 is positioned at rank #492 in our cost-efficiency ranking, representing a Lower cost-benefit for your build. Components placed above yours deliver better value for money.
Avg price is the current average price collected from markets across the web.
Performance Per Dollar Phenom II X2 B55
Performance Per Dollar Ryzen 9 5900X
Performance Comparison
About PassMark🏆 Chipversus Verdict
🚀 Performance Leadership
| Insight | Phenom II X2 B55 | Ryzen 9 5900X |
|---|---|---|
| Gaming | ❌ Lower gaming performance | ✅ Superior gaming performance |
| Workstation | ❌ Weaker in multi-core tasks | ✅ Better multi-core power |
| Price | ✅ More affordable ($0) | ⚠️ Higher cost ($350) |
| Longevity | 🛑 Legacy (Callisto (2009−2010) / 45 nm) | ✨ Modern (Vermeer (Zen3) (2020−2022) / 7 nm, 12 nm) |
💎 Value Proposition
| Insight | Phenom II X2 B55 | Ryzen 9 5900X |
|---|---|---|
| Cost Efficiency | ❌ Lower cost efficiency | ❌ Lower cost efficiency |
| Upfront Cost | ✅ More affordable ($0) | ⚠️ Higher cost ($350) |
Performance Check
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.
Technical Specifications
Side-by-side comparison of Phenom II X2 B55 and Ryzen 9 5900X

Phenom II X2 B55
The Phenom II X2 B55 is manufactured by AMD. It was released in 1 October 2009 (16 years ago). It is based on the Callisto (2009−2010) architecture. It features 2 cores and 2 threads. Base frequency is 3 GHz, with boost up to 3 GHz. L3 cache: 6 MB (total). L2 cache: 512 kB (per core). Built on 45 nm process technology. Socket: AM3. Thermal design power (TDP): 80 Watt. Memory support: DDR3. Passmark benchmark score: 1,222 points. Launch price was $48.

Ryzen 9 5900X
The Ryzen 9 5900X is manufactured by AMD. It was released in 5 November 2020 (5 years ago). It is based on the Vermeer (Zen3) (2020−2022) architecture. It features 12 cores and 24 threads. Base frequency is 3.7 GHz, with boost up to 4.8 GHz. L3 cache: 64 MB. L2 cache: 512K (per core). Built on 7 nm, 12 nm process technology. Socket: AM4. Thermal design power (TDP): 105 Watt. Memory support: DDR4-3200. Passmark benchmark score: 38,955 points. Launch price was $549.
Processing Power
The Phenom II X2 B55 packs 2 cores / 2 threads, while the Ryzen 9 5900X offers 12 cores / 24 threads — the Ryzen 9 5900X has 10 more cores. Boost clocks reach 3 GHz on the Phenom II X2 B55 versus 4.8 GHz on the Ryzen 9 5900X — a 46.2% clock advantage for the Ryzen 9 5900X (base: 3 GHz vs 3.7 GHz). The Phenom II X2 B55 uses the Callisto (2009−2010) architecture (45 nm), while the Ryzen 9 5900X uses Vermeer (Zen3) (2020−2022) (7 nm, 12 nm). In PassMark, the Phenom II X2 B55 scores 1,222 against the Ryzen 9 5900X's 38,955 — a 187.8% lead for the Ryzen 9 5900X. L3 cache: 6 MB (total) on the Phenom II X2 B55 vs 64 MB on the Ryzen 9 5900X.
| Feature | Phenom II X2 B55 | Ryzen 9 5900X |
|---|---|---|
| Cores / Threads | 2 / 2 | 12 / 24+500% |
| Boost Clock | 3 GHz | 4.8 GHz+60% |
| Base Clock | 3 GHz | 3.7 GHz+23% |
| L3 Cache | 6 MB (total) | 64 MB+967% |
| L2 Cache | 512 kB (per core) | 512K (per core) |
| Process | 45 nm | 7 nm, 12 nm-84% |
| Architecture | Callisto (2009−2010) | Vermeer (Zen3) (2020−2022) |
| PassMark | 1,222 | 38,955+3088% |
| Cinebench R23 Multi | — | 21,000 |
| Geekbench 6 Single | — | 2,174 |
| Geekbench 6 Multi | — | 11,888 |
Memory & Platform
The Phenom II X2 B55 uses the AM3 socket (PCIe 2.0), while the Ryzen 9 5900X uses AM4 (PCIe 4.0) — making them incompatible on the same motherboard.
| Feature | Phenom II X2 B55 | Ryzen 9 5900X |
|---|---|---|
| Socket | AM3 | AM4 |
| PCIe Generation | PCIe 2.0 | PCIe 4.0+100% |
| Max RAM Speed | — | DDR4-3200 |
| Max RAM Capacity | — | 128 GB |
| RAM Channels | — | 2 |
| ECC Support | — | ✅ |
| PCIe Lanes | — | 24 |
Advanced Features
Virtualization: not specified (Phenom II X2 B55) / AMD-V (Ryzen 9 5900X). Primary use case: Ryzen 9 5900X targets Workstation. Direct competitor: Ryzen 9 5900X rivals Core i9-12900K.
| Feature | Phenom II X2 B55 | Ryzen 9 5900X |
|---|---|---|
| Integrated GPU | — | No |
| Unlocked | — | Yes |
| AVX-512 | — | No |
| Virtualization | — | AMD-V |
| Target Use | — | Workstation |
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