i7-1255U vs i9-7940X
Aggregate performance score
Core i9-7940X outperforms Core i7-1255U by an impressive 92% based on our aggregate benchmark results.
Primary details
Comparing Core i9-7940X and Core i7-1255U processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 408 | 896 |
| Place by popularity | not in top-100 | 74 |
| Cost-effectiveness evaluation | 3.30 | no data |
| Market segment | Desktop processor | Laptop |
| Series | Intel Core i9 | Intel Alder Lake-M |
| Power efficiency | 9.37 | 53.78 |
| Architecture codename | Skylake (server) (2017−2018) | Alder Lake-U (2022) |
| Release date | 1 September 2017 (7 years ago) | 23 February 2022 (2 years ago) |
| Launch price (MSRP) | $1,399 | no data |
Cost-effectiveness evaluation
Performance per price, higher is better.
Detailed specifications
Core i9-7940X and Core i7-1255U 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 | 14 (Tetradeca-Core) | 10 (Deca-Core) |
| Threads | 28 | 12 |
| Base clock speed | 3.1 GHz | 1.7 GHz |
| Boost clock speed | 4.4 GHz | 4.7 GHz |
| Bus type | DMI 3.0 | no data |
| Bus rate | 4 × 8 GT/s | no data |
| L1 cache | 64 KB (per core) | 80K (per core) |
| L2 cache | 1 MB (per core) | 1.25 MB (per core) |
| L3 cache | 19.25 MB (shared) | 12 MB (shared) |
| Chip lithography | 14 nm | 10 nm |
| Die size | 484 mm2 | no data |
| Maximum core temperature | 102 °C | 100 °C |
| 64 bit support | + | + |
| Windows 11 compatibility | + | + |
| Unlocked multiplier | + | - |
Compatibility
Information on Core i9-7940X and Core i7-1255U 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 | FCLGA2066 | Intel BGA 1744 |
| Power consumption (TDP) | 165 Watt | 15 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Core i9-7940X and Core i7-1255U. You'll probably need this information if you require some particular technology.
| Instruction set extensions | Intel® SSE4.1, Intel® SSE4.2, Intel® AVX2, Intel® AVX-512 | no data |
| AES-NI | + | + |
| FMA | - | + |
| AVX | + | + |
| Enhanced SpeedStep (EIST) | + | + |
| Turbo Boost Technology | 2.0 | no data |
| Hyper-Threading Technology | + | no data |
| TSX | + | + |
| Turbo Boost Max 3.0 | + | no data |
Security technologies
Core i9-7940X and Core i7-1255U technologies aimed at improving security, for example, by protecting against hacks.
| TXT | no data | + |
| EDB | + | no data |
Virtualization technologies
Virtual machine speed-up technologies supported by Core i9-7940X and Core i7-1255U are enumerated here.
| VT-d | + | + |
| VT-x | + | + |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Core i9-7940X and Core i7-1255U. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR4-2666 | DDR4, DDR5 |
| Maximum memory size | 128 GB | no data |
| Max memory channels | 4 | no data |
| Maximum memory bandwidth | 85.33 GB/s | no data |
Graphics specifications
General parameters of integrated GPUs, if any.
| Integrated graphics card | N/A | Intel Iris Xe Graphics G7 96EUs ( - 1250 MHz) |
Peripherals
Specifications and connection of peripherals supported by Core i9-7940X and Core i7-1255U.
| PCIe version | 3.0 | 4.0 |
| PCI Express lanes | 44 | 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 | 16.34 | 8.53 |
| Recency | 1 September 2017 | 23 February 2022 |
| Physical cores | 14 | 10 |
| Threads | 28 | 12 |
| Chip lithography | 14 nm | 10 nm |
| Power consumption (TDP) | 165 Watt | 15 Watt |
i9-7940X has a 91.6% higher aggregate performance score, and 40% more physical cores and 133.3% more threads.
i7-1255U, on the other hand, has an age advantage of 4 years, a 40% more advanced lithography process, and 1000% lower power consumption.
The Core i9-7940X is our recommended choice as it beats the Core i7-1255U in performance tests.
Note that Core i9-7940X is a desktop processor while Core i7-1255U is a notebook one.
Should you still have questions on choice between Core i9-7940X and Core i7-1255U, ask them in Comments section, and we shall answer.
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