Athlon X4 840 vs Athlon II X4 651
Aggregate performance score
Athlon II X4 651 outperforms Athlon X4 840 by a small 8% based on our aggregate benchmark results.
Primary details
Comparing Athlon II X4 651 and Athlon X4 840 processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 1817 | 1875 |
| Place by popularity | not in top-100 | not in top-100 |
| Market segment | Desktop processor | Desktop processor |
| Series | no data | 4x Athlon |
| Power efficiency | 2.14 | 3.04 |
| Architecture codename | Llano (2011−2012) | Kaveri (2014−2015) |
| Release date | 14 November 2011 (13 years ago) | August 2014 (10 years ago) |
Detailed specifications
Athlon II X4 651 and Athlon X4 840 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 GHz | 3.1 GHz |
| Boost clock speed | 3 GHz | 3.8 GHz |
| L1 cache | 128 KB (per core) | 256K |
| L2 cache | 1 MB (per core) | 4 MB |
| L3 cache | 0 KB | no data |
| Chip lithography | 32 nm | 28 nm |
| Die size | 228 mm2 | 245 mm2 |
| Maximum case temperature (TCase) | no data | 72 °C |
| Number of transistors | 1,178 million | 2,411 million |
| 64 bit support | + | + |
| Windows 11 compatibility | - | - |
| Unlocked multiplier | - | + |
Compatibility
Information on Athlon II X4 651 and Athlon X4 840 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 | FM1 | Socket FM2+ |
| Power consumption (TDP) | 100 Watt | 65 watt |
Technologies and extensions
Technological solutions and additional instructions supported by Athlon II X4 651 and Athlon X4 840. 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 II X4 651 and Athlon X4 840 are enumerated here.
| AMD-V | + | + |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Athlon II X4 651 and Athlon X4 840. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR3 | DDR3 |
Peripherals
Specifications and connection of peripherals supported by Athlon II X4 651 and Athlon X4 840.
| PCIe version | no data | 3.0 |
| PCI Express lanes | no data | 16 |
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 | 2.26 | 2.09 |
| Recency | 14 November 2011 | on August 2014 |
| Chip lithography | 32 nm | 28 nm |
| Power consumption (TDP) | 100 Watt | 65 Watt |
Athlon II X4 651 has a 8.1% higher aggregate performance score.
Athlon X4 840, on the other hand, has an age advantage of 2 years, a 14.3% more advanced lithography process, and 53.8% lower power consumption.
Given the minimal performance differences, no clear winner can be declared between Athlon II X4 651 and Athlon X4 840.
Should you still have questions on choice between Athlon II X4 651 and Athlon X4 840, ask them in Comments section, and we shall answer.
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