Athlon II X4 645 vs Athlon X4 840
Aggregate performance score
Athlon X4 840 outperforms Athlon II X4 645 by a considerable 41% based on our aggregate benchmark results.
Primary details
Comparing Athlon X4 840 and Athlon II X4 645 processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 1890 | 2167 |
| Place by popularity | not in top-100 | not in top-100 |
| Cost-effectiveness evaluation | no data | 3.30 |
| Market segment | Desktop processor | Desktop processor |
| Series | 4x Athlon | no data |
| Power efficiency | 3.04 | 1.47 |
| Architecture codename | Kaveri (2014−2015) | Propus (2009−2011) |
| Release date | August 2014 (10 years ago) | 21 September 2010 (14 years ago) |
| Launch price (MSRP) | no data | $80 |
Cost-effectiveness evaluation
Performance per price, higher is better.
Detailed specifications
Athlon X4 840 and Athlon II X4 645 basic parameters such as number of cores, number of threads, base frequency and turbo boost clock, lithography, cache size and multiplier lock state. These parameters indirectly say of CPU speed, though for more precise assessment you have to consider their test results.
| Physical cores | 4 (Quad-Core) | 4 (Quad-Core) |
| Threads | 4 | 4 |
| Base clock speed | 3.1 GHz | 3.1 GHz |
| Boost clock speed | 3.8 GHz | 3.1 GHz |
| L1 cache | 256K | 128 KB (per core) |
| L2 cache | 4 MB | 512 KB (per core) |
| L3 cache | no data | 0 KB |
| Chip lithography | 28 nm | 45 nm |
| Die size | 245 mm2 | 169 mm2 |
| Maximum case temperature (TCase) | 72 °C | no data |
| Number of transistors | 2,411 million | 300 million |
| 64 bit support | + | + |
| Windows 11 compatibility | - | - |
| Unlocked multiplier | + | - |
Compatibility
Information on Athlon X4 840 and Athlon II X4 645 compatibility with other computer components: motherboard (look for socket type), power supply unit (look for power consumption) etc. Useful when planning a future computer configuration or upgrading an existing one. Note that power consumption of some processors can well exceed their nominal TDP, even without overclocking. Some can even double their declared thermals given that the motherboard allows to tune the CPU power parameters.
| Number of CPUs in a configuration | 1 | 1 |
| Socket | Socket FM2+ | AM3 |
| Power consumption (TDP) | 65 watt | 95 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Athlon X4 840 and Athlon II X4 645. You'll probably need this information if you require some particular technology.
| AES-NI | + | - |
| FMA | + | - |
| AVX | + | - |
Virtualization technologies
Virtual machine speed-up technologies supported by Athlon X4 840 and Athlon II X4 645 are enumerated here.
| AMD-V | + | - |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Athlon X4 840 and Athlon II X4 645. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR3 | DDR3 |
Peripherals
Specifications and connection of peripherals supported by Athlon X4 840 and Athlon II X4 645.
| PCIe version | 3.0 | 2.0 |
| PCI Express lanes | 16 | no data |
Synthetic benchmark performance
Various benchmark results of the processors in comparison. Overall score is measured in points in 0-100 range, higher is better.
Combined synthetic benchmark score
This is our combined benchmark performance rating. We are regularly improving our combining algorithms, but if you find some perceived inconsistencies, feel free to speak up in comments section, we usually fix problems quickly.
Passmark
Passmark CPU Mark is a widespread benchmark, consisting of 8 different types of workload, including integer and floating point math, extended instructions, compression, encryption and physics calculation. There is also one separate single-threaded scenario measuring single-core performance.
GeekBench 5 Single-Core
GeekBench 5 Single-Core is a cross-platform application developed in the form of CPU tests that independently recreate certain real-world tasks with which to accurately measure performance. This version uses only a single CPU core.
GeekBench 5 Multi-Core
GeekBench 5 Multi-Core is a cross-platform application developed in the form of CPU tests that independently recreate certain real-world tasks with which to accurately measure performance. This version uses all available CPU cores.
Pros & cons summary
| Performance score | 2.09 | 1.48 |
| Recency | on August 2014 | 21 September 2010 |
| Chip lithography | 28 nm | 45 nm |
| Power consumption (TDP) | 65 Watt | 95 Watt |
Athlon X4 840 has a 41.2% higher aggregate performance score, an age advantage of 3 years, a 60.7% more advanced lithography process, and 46.2% lower power consumption.
The Athlon X4 840 is our recommended choice as it beats the Athlon II X4 645 in performance tests.
Should you still have questions on choice between Athlon X4 840 and Athlon II X4 645, ask them in Comments section, and we shall answer.
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