A6-6400B vs Athlon II X4 645
Aggregate performance score
Athlon II X4 645 outperforms A6-6400B by a considerable 45% based on our aggregate benchmark results.
Primary details
Comparing Athlon II X4 645 and A6-6400B processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 2168 | 2461 |
| Place by popularity | not in top-100 | not in top-100 |
| Cost-effectiveness evaluation | 3.30 | no data |
| Market segment | Desktop processor | Desktop processor |
| Power efficiency | 1.47 | 1.49 |
| Architecture codename | Propus (2009−2011) | Richland (2013−2014) |
| Release date | 21 September 2010 (14 years ago) | 1 June 2013 (11 years ago) |
| Launch price (MSRP) | $80 | no data |
Cost-effectiveness evaluation
Performance per price, higher is better.
Detailed specifications
Athlon II X4 645 and A6-6400B 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) | 2 (Dual-core) |
| Threads | 4 | 2 |
| Base clock speed | 3.1 GHz | 3.9 GHz |
| Boost clock speed | 3.1 GHz | 4.1 GHz |
| L1 cache | 128 KB (per core) | 96K |
| L2 cache | 512 KB (per core) | 1 MB (shared) |
| L3 cache | 0 KB | no data |
| Chip lithography | 45 nm | 32 nm |
| Die size | 169 mm2 | 246 mm2 |
| Maximum case temperature (TCase) | no data | 70 °C |
| Number of transistors | 300 million | 1,303 million |
| 64 bit support | + | + |
| Windows 11 compatibility | - | no data |
| Unlocked multiplier | - | + |
Compatibility
Information on Athlon II X4 645 and A6-6400B 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 | AM3 | FM2 |
| Power consumption (TDP) | 95 Watt | 65 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Athlon II X4 645 and A6-6400B. You'll probably need this information if you require some particular technology.
| AES-NI | - | + |
| FMA | - | + |
| AVX | - | + |
| PowerNow | - | + |
Virtualization technologies
Virtual machine speed-up technologies supported by Athlon II X4 645 and A6-6400B are enumerated here.
| AMD-V | - | + |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Athlon II X4 645 and A6-6400B. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR3 | DDR3-1866 |
Graphics specifications
General parameters of integrated GPUs, if any.
| Integrated graphics card | no data | AMD Radeon HD 8470D |
Peripherals
Specifications and connection of peripherals supported by Athlon II X4 645 and A6-6400B.
| PCIe version | 2.0 | 2.0 |
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.
Pros & cons summary
| Performance score | 1.48 | 1.02 |
| Recency | 21 September 2010 | 1 June 2013 |
| Physical cores | 4 | 2 |
| Threads | 4 | 2 |
| Chip lithography | 45 nm | 32 nm |
| Power consumption (TDP) | 95 Watt | 65 Watt |
Athlon II X4 645 has a 45.1% higher aggregate performance score, and 100% more physical cores and 100% more threads.
A6-6400B, on the other hand, has an age advantage of 2 years, a 40.6% more advanced lithography process, and 46.2% lower power consumption.
The Athlon II X4 645 is our recommended choice as it beats the A6-6400B in performance tests.
Should you still have questions on choice between Athlon II X4 645 and A6-6400B, ask them in Comments section, and we shall answer.
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