Core i9-12900K vs FX-8120
Aggregate performance score
i9-12900K outperforms FX-8120 by a whopping 530% based on our aggregate benchmark results.
Primary details
Comparing FX-8120 and Core i9-12900K processor market type (desktop or notebook), architecture, sales start time and price.
| Place in performance ranking | 1308 | 162 |
| Place by popularity | not in top-100 | not in top-100 |
| Cost-effectiveness evaluation | 2.74 | 68.35 |
| Market segment | Desktop processor | Desktop processor |
| Series | no data | Intel Core i9 |
| Architecture codename | Zambezi (2011−2012) | Alder Lake |
| Release date | 12 October 2011 (12 years ago) | 5 November 2021 (2 years ago) |
| Launch price (MSRP) | no data | $589 |
| Current price | $68 | $367 (0.6x MSRP) |
Cost-effectiveness evaluation
Performance per price, higher is better.
i9-12900K has 2395% better value for money than FX-8120.
Detailed specifications
FX-8120 and Core i9-12900K 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 | 8 (Octa-Core) | 16 (Hexadeca-Core) |
| Threads | 8 | 24 |
| Base clock speed | 3.1 GHz | 3.2 GHz |
| Boost clock speed | 4 GHz | 5.2 GHz |
| L1 cache | 384 KB | 1.4 MB |
| L2 cache | 8 MB | 14 MB |
| L3 cache | 8 MB (shared) | 30 MB |
| Chip lithography | 32 nm | 10 nm |
| Die size | 315 mm2 | 215.25 mm2"20.5 mm × 10.5 mm |
| Maximum core temperature | no data | 100 °C |
| Maximum case temperature (TCase) | no data | 72 °C |
| Number of transistors | 1,200 million | no data |
| 64 bit support | + | + |
| Windows 11 compatibility | - | + |
| Unlocked multiplier | Yes | Yes |
Compatibility
Information on FX-8120 and Core i9-12900K 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+ | LGA1700 |
| Power consumption (TDP) | 125 Watt | 125 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by FX-8120 and Core i9-12900K. You'll probably need this information if you require some particular technology.
| AES-NI | + | + |
| FMA | + | no data |
| AVX | + | + |
| vPro | no data | + |
| Enhanced SpeedStep (EIST) | no data | + |
Virtualization technologies
Virtual machine speed-up technologies supported by FX-8120 and Core i9-12900K are enumerated here.
| AMD-V | + | no data |
| VT-d | no data | + |
| VT-x | no data | + |
Memory specs
Types, maximum amount and channel quantity of RAM supported by FX-8120 and Core i9-12900K. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR3 | DDR4, DDR5 |
| Maximum memory size | no data | 128 GB |
| Maximum memory bandwidth | no data | 76.805 GB/s |
| ECC memory support | no data | + |
Graphics specifications
General parameters of integrated GPUs, if any.
| Integrated graphics card | no data | Intel UHD Graphics 770 |
Peripherals
Specifications and connection of peripherals supported by FX-8120 and Core i9-12900K.
| PCIe version | 2.0 | 5.0 |
| PCI Express lanes | no data | 20 |
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.
Core i9-12900K outperforms FX-8120 by 530% based on our aggregate benchmark results.
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.
Benchmark coverage: 68%
Core i9-12900K outperforms FX-8120 by 529% in Passmark.
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.
Benchmark coverage: 42%
Core i9-12900K outperforms FX-8120 by 520% in GeekBench 5 Single-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.
Benchmark coverage: 42%
Core i9-12900K outperforms FX-8120 by 892% in GeekBench 5 Multi-Core.
Pros & cons summary
| Performance score | 4.26 | 26.82 |
| Recency | 12 October 2011 | 5 November 2021 |
| Physical cores | 8 | 16 |
| Threads | 8 | 24 |
| Chip lithography | 32 nm | 10 nm |
i9-12900K has a 529.6% higher aggregate performance score, an age advantage of 10 years, 100% more physical cores and 200% more threads, and a 220% more advanced lithography process.
The Core i9-12900K is our recommended choice as it beats the FX-8120 in performance tests.
Should you still have questions on choice between FX-8120 and Core i9-12900K, ask them in Comments section, and we shall answer.
Similar processor comparisons
We picked several similar comparisons of processors in the same market segment and performance relatively close to those reviewed on this page.
