A8-3870K vs Athlon II X4 645
A8-3870K
Athlon II X4 645
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. Components placed above yours deliver better value for money. The A8-3870K is positioned at rank 502 and the Athlon II X4 645 is on rank 819, so the A8-3870K offers better cost-efficiency for playing games.
Avg price is the current average price collected from markets across the web.
Performance Per Dollar A8-3870K
Performance Per Dollar Athlon II X4 645
Performance Comparison
About PassMark🏆 Chipversus Verdict
🚀 Performance Leadership
| Insight | A8-3870K | Athlon II X4 645 |
|---|---|---|
| Gaming | ❌ Lower gaming performance | ✅ Superior gaming performance |
| Workstation | ❌ Weaker in multi-core tasks | ✅ Better multi-core power |
| Price | ✅ More affordable ($0) | ⚠️ Higher cost ($20) |
| Longevity | 🛑 Legacy (Llano (2011−2012) / 32 nm) | 🛑 Legacy (Propus (2009−2011) / 45 nm) |
💎 Value Proposition
| Insight | A8-3870K | Athlon II X4 645 |
|---|---|---|
| Cost Efficiency | ❌ Lower cost efficiency | ❌ Lower cost efficiency |
| Upfront Cost | ✅ More affordable ($0) | ⚠️ Higher cost ($20) |
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 A8-3870K and Athlon II X4 645
A8-3870K
The A8-3870K is manufactured by AMD. It was released in 2014-01-01. It is based on the Llano (2011−2012) architecture. It features 4 cores and 4 threads. Base frequency is 3 GHz, with boost up to 3 GHz. L3 cache: 0 kB. L2 cache: 1 MB (per core). Built on 32 nm process technology. Socket: FM1. Thermal design power (TDP): 100 Watt. Memory support: DDR3. Passmark benchmark score: 2,360 points. Launch price was $90.
Athlon II X4 645
The Athlon II X4 645 is manufactured by AMD. It was released in 21 September 2010 (15 years ago). It is based on the Propus (2009−2011) architecture. It features 4 cores and 4 threads. Base frequency is 3.1 GHz, with boost up to 3.1 GHz. L3 cache: 0 kB. L2 cache: 512 kB (per core). Built on 45 nm process technology. Socket: AM3. Thermal design power (TDP): 95 Watt. Memory support: DDR3. Passmark benchmark score: 2,375 points. Launch price was $80.
Processing Power
Both the A8-3870K and Athlon II X4 645 share an identical 4-core/4-thread configuration. Boost clocks reach 3 GHz on the A8-3870K versus 3.1 GHz on the Athlon II X4 645 — a 3.3% clock advantage for the Athlon II X4 645 (base: 3 GHz vs 3.1 GHz). The A8-3870K uses the Llano (2011−2012) architecture (32 nm), while the Athlon II X4 645 uses Propus (2009−2011) (45 nm). In PassMark, the A8-3870K scores 2,360 against the Athlon II X4 645's 2,375 — a 0.6% lead for the Athlon II X4 645. Geekbench 6 single-core — the metric most relevant to gaming — records 380 vs 399, a 4.9% lead for the Athlon II X4 645 that directly translates to higher frame rates. Both processors carry 0 kB of L3 cache.
| Feature | A8-3870K | Athlon II X4 645 |
|---|---|---|
| Cores / Threads | 4 / 4 | 4 / 4 |
| Boost Clock | 3 GHz | 3.1 GHz+3% |
| Base Clock | 3 GHz | 3.1 GHz+3% |
| L3 Cache | 0 kB | 0 kB |
| L2 Cache | 1 MB (per core)+100% | 512 kB (per core) |
| Process | 32 nm-29% | 45 nm |
| Architecture | Llano (2011−2012) | Propus (2009−2011) |
| PassMark | 2,360 | 2,375 |
| Cinebench R23 Multi | — | 1,374 |
| Geekbench 6 Single | 380 | 399+5% |
| Geekbench 6 Multi | — | 1,374 |
Memory & Platform
The A8-3870K uses the FM1 socket (PCIe 2.0), while the Athlon II X4 645 uses AM3 (PCIe 2.0) — making them incompatible on the same motherboard. Both support up to DDR3-1866 memory speed. The A8-3870K supports up to 32 GB of RAM compared to 16 GB — 66.7% more capacity for professional workloads. Both feature 2-channel memory with ECC support. PCIe lanes: 20 (A8-3870K) vs 16 (Athlon II X4 645) — the A8-3870K offers 4 more lanes for additional GPUs or NVMe drives. Chipset compatibility: A55,A75 (A8-3870K) and AMD 700 Series,AMD 800 Series,AMD 900 Series (Athlon II X4 645).
| Feature | A8-3870K | Athlon II X4 645 |
|---|---|---|
| Socket | FM1 | AM3 |
| PCIe Generation | PCIe 2.0 | PCIe 2.0 |
| Max RAM Speed | DDR3-1866 | DDR3-1333 |
| Max RAM Capacity | 32 GB+100% | 16 GB |
| RAM Channels | 2 | 2 |
| ECC Support | ❌ | ❌ |
| PCIe Lanes | 20+25% | 16 |
Advanced Features
Virtualization support: AMD-V (A8-3870K) vs Yes (Athlon II X4 645). The A8-3870K includes integrated graphics (Radeon HD 6550D), while the Athlon II X4 645 requires a dedicated GPU. Primary use case: A8-3870K targets Budget Gaming Desktop, Athlon II X4 645 targets Desktop. Direct competitor: A8-3870K rivals Core i3-2125.
| Feature | A8-3870K | Athlon II X4 645 |
|---|---|---|
| Integrated GPU | Yes | No |
| IGPU Model | Radeon HD 6550D | — |
| Unlocked | Yes | — |
| AVX-512 | No | No |
| Virtualization | AMD-V | Yes |
| Target Use | Budget Gaming Desktop | Desktop |
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