Ryzen 7 7840H vs Ryzen 9 3900X
Aggregate performance score
Ryzen 9 3900X outperforms Ryzen 7 7840H by a moderate 15% based on our aggregate benchmark results.
Primary details
Comparing Ryzen 9 3900X and Ryzen 7 7840H processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 275 | 348 |
| Place by popularity | not in top-100 | not in top-100 |
| Cost-effectiveness evaluation | 21.75 | no data |
| Market segment | Desktop processor | Laptop |
| Series | AMD Ryzen 9 | no data |
| Power efficiency | 15.55 | 48.30 |
| Architecture codename | Matisse (Zen 2) (2019−2020) | Phoenix (2023−2024) |
| Release date | 7 July 2019 (5 years ago) | January 2023 (1 year ago) |
| Launch price (MSRP) | $499 | no data |
Cost-effectiveness evaluation
Performance per price, higher is better.
Detailed specifications
Ryzen 9 3900X and Ryzen 7 7840H 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 | 12 (Dodeca-Core) | 8 (Octa-Core) |
| Threads | 24 | 16 |
| Base clock speed | 3.8 GHz | 3.8 GHz |
| Boost clock speed | 4.6 GHz | 5.1 GHz |
| L1 cache | 96K (per core) | 64K (per core) |
| L2 cache | 512K (per core) | 1 MB (per core) |
| L3 cache | 64 MB | 16 MB (shared) |
| Chip lithography | 7 nm, 12 nm | 4 nm |
| Die size | no data | 178 mm2 |
| Maximum core temperature | 95 °C | no data |
| Number of transistors | 19,200 million | 25,000 million |
| 64 bit support | + | + |
| Windows 11 compatibility | + | + |
| Unlocked multiplier | + | - |
Compatibility
Information on Ryzen 9 3900X and Ryzen 7 7840H 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 (Uniprocessor) | 1 |
| Socket | AM4 | FP8 |
| Power consumption (TDP) | 125 Watt | 35 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Ryzen 9 3900X and Ryzen 7 7840H. You'll probably need this information if you require some particular technology.
| AES-NI | + | + |
| AVX | + | + |
| Precision Boost 2 | + | + |
Virtualization technologies
Virtual machine speed-up technologies supported by Ryzen 9 3900X and Ryzen 7 7840H are enumerated here.
| AMD-V | + | + |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Ryzen 9 3900X and Ryzen 7 7840H. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR4 Dual-channel | DDR5-5600 |
| Maximum memory size | 128 GB | no data |
| Max memory channels | 2 | no data |
| Maximum memory bandwidth | 51.196 GB/s | no data |
Graphics specifications
General parameters of integrated GPUs, if any.
| Integrated graphics card | - | AMD Radeon 780M |
Peripherals
Specifications and connection of peripherals supported by Ryzen 9 3900X and Ryzen 7 7840H.
| PCIe version | no data | 4.0 |
| 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.
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 | 20.53 | 17.85 |
| Physical cores | 12 | 8 |
| Threads | 24 | 16 |
| Chip lithography | 7 nm | 4 nm |
| Power consumption (TDP) | 125 Watt | 35 Watt |
Ryzen 9 3900X has a 15% higher aggregate performance score, and 50% more physical cores and 50% more threads.
Ryzen 7 7840H, on the other hand, has a 75% more advanced lithography process, and 257.1% lower power consumption.
The Ryzen 9 3900X is our recommended choice as it beats the Ryzen 7 7840H in performance tests.
Note that Ryzen 9 3900X is a desktop processor while Ryzen 7 7840H is a notebook one.
Should you still have questions on choice between Ryzen 9 3900X and Ryzen 7 7840H, ask them in Comments section, and we shall answer.
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