Ryzen 9 9900X vs Athlon II X4 651K
Primary details
Comparing Athlon II X4 651K and Ryzen 9 9900X processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | not rated | 108 |
| Place by popularity | not in top-100 | not in top-100 |
| Cost-effectiveness evaluation | no data | 63.62 |
| Market segment | Desktop processor | Desktop processor |
| Power efficiency | no data | 27.28 |
| Architecture codename | Llano (2011−2012) | Granite Ridge (2024) |
| Release date | 14 November 2011 (13 years ago) | 15 August 2024 (less than a year ago) |
| Launch price (MSRP) | no data | $499 |
Cost-effectiveness evaluation
Performance per price, higher is better.
Detailed specifications
Athlon II X4 651K and Ryzen 9 9900X 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) | 12 (Dodeca-Core) |
| Threads | 4 | 24 |
| Base clock speed | 3 GHz | 4.4 GHz |
| Boost clock speed | 3 GHz | 5.6 GHz |
| L1 cache | 128 KB (per core) | 80 KB (per core) |
| L2 cache | 1 MB (per core) | 1 MB (per core) |
| L3 cache | 0 KB | 64 MB (shared) |
| Chip lithography | 32 nm | 4 nm |
| Die size | 228 mm2 | 2x 70.6 mm2 |
| Maximum core temperature | no data | 95 °C |
| Number of transistors | 1,178 million | 16,630 million |
| 64 bit support | + | + |
| Windows 11 compatibility | - | no data |
| Unlocked multiplier | - | + |
Compatibility
Information on Athlon II X4 651K and Ryzen 9 9900X 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 | AM5 |
| Power consumption (TDP) | 100 Watt | 120 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Athlon II X4 651K and Ryzen 9 9900X. You'll probably need this information if you require some particular technology.
| Instruction set extensions | no data | SMT, AES, AVX, AVX2, AVX512, FMA3, MMX (+), SHA, SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2, SSE4A |
| AES-NI | - | + |
| AVX | - | + |
| Precision Boost 2 | no data | + |
Virtualization technologies
Virtual machine speed-up technologies supported by Athlon II X4 651K and Ryzen 9 9900X are enumerated here.
| AMD-V | + | + |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Athlon II X4 651K and Ryzen 9 9900X. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR3 | DDR5 |
Graphics specifications
General parameters of integrated GPUs, if any.
| Integrated graphics card | no data | AMD Radeon Graphics |
Peripherals
Specifications and connection of peripherals supported by Athlon II X4 651K and Ryzen 9 9900X.
| PCIe version | no data | 5.0 |
| PCI Express lanes | no data | 24 |
Pros & cons summary
| Recency | 14 November 2011 | 15 August 2024 |
| Physical cores | 4 | 12 |
| Threads | 4 | 24 |
| Chip lithography | 32 nm | 4 nm |
| Power consumption (TDP) | 100 Watt | 120 Watt |
Athlon II X4 651K has 20% lower power consumption.
Ryzen 9 9900X, on the other hand, has an age advantage of 12 years, 200% more physical cores and 500% more threads, and a 700% more advanced lithography process.
We couldn't decide between Athlon II X4 651K and Ryzen 9 9900X. We've got no test results to judge.
Should you still have questions on choice between Athlon II X4 651K and Ryzen 9 9900X, ask them in Comments section, and we shall answer.
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