Athlon 64 FX-55 vs Athlon II X4 645
Aggregate performance score
Athlon II X4 645 outperforms Athlon 64 FX-55 by a whopping 492% based on our aggregate benchmark results.
Primary details
Comparing Athlon II X4 645 and Athlon 64 FX-55 processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 2167 | 3163 |
| 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 | 0.23 |
| Architecture codename | Propus (2009−2011) | Clawhammer (2001−2005) |
| Release date | 21 September 2010 (14 years ago) | 10 October 2004 (20 years ago) |
| Launch price (MSRP) | $80 | $180 |
Cost-effectiveness evaluation
Performance per price, higher is better.
Athlon II X4 645 and Athlon 64 FX-55 have a nearly equal value for money.
Detailed specifications
Athlon II X4 645 and Athlon 64 FX-55 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) | 1 (Single-Core) |
| Threads | 4 | 1 |
| Base clock speed | 3.1 GHz | 2.6 GHz |
| Boost clock speed | 3.1 GHz | 2.6 GHz |
| L1 cache | 128 KB (per core) | 128 KB |
| L2 cache | 512 KB (per core) | 1 MB |
| L3 cache | 0 KB | 0 KB |
| Chip lithography | 45 nm | 130 nm |
| Die size | 169 mm2 | 193 mm2 |
| Maximum case temperature (TCase) | no data | 63 °C |
| Number of transistors | 300 million | 105 million |
| 64 bit support | + | + |
| Windows 11 compatibility | - | - |
| Unlocked multiplier | - | + |
Compatibility
Information on Athlon II X4 645 and Athlon 64 FX-55 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 | 939 |
| Power consumption (TDP) | 95 Watt | 104 Watt |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Athlon II X4 645 and Athlon 64 FX-55. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR3 | DDR1 Depends on motherboard |
Graphics specifications
General parameters of integrated GPUs, if any.
| Integrated graphics card | no data | On certain motherboards (Chipset feature) |
Peripherals
Specifications and connection of peripherals supported by Athlon II X4 645 and Athlon 64 FX-55.
| PCIe version | 2.0 | 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.
Pros & cons summary
| Performance score | 1.48 | 0.25 |
| Recency | 21 September 2010 | 10 October 2004 |
| Physical cores | 4 | 1 |
| Threads | 4 | 1 |
| Chip lithography | 45 nm | 130 nm |
| Power consumption (TDP) | 95 Watt | 104 Watt |
Athlon II X4 645 has a 492% higher aggregate performance score, an age advantage of 5 years, 300% more physical cores and 300% more threads, a 188.9% more advanced lithography process, and 9.5% lower power consumption.
The Athlon II X4 645 is our recommended choice as it beats the Athlon 64 FX-55 in performance tests.
Should you still have questions on choice between Athlon II X4 645 and Athlon 64 FX-55, ask them in Comments section, and we shall answer.
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