3 N355 vs Ultra 7 251HX
Aggregate performance score
Core Ultra 7 251HX outperforms Core 3 N355 by a whopping 355% based on our aggregate benchmark results.
Contents
Primary details
Comparing processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 261 | 1398 |
| Place by popularity | not in top-100 | not in top-100 |
| Market segment | Laptop | Laptop |
| Series | Intel Arrow Lake | no data |
| Power efficiency | 6.99 | 16.39 |
| Designer | Intel | Intel |
| Manufacturer | no data | Intel |
| Architecture codename | Arrow Lake-HX (2025−2026) | Twin Lake (2024−2025) |
| Release date | 1 April 2026 (less than a year ago) | 7 January 2025 (1 year ago) |
Detailed specifications
Basic parameters of Core Ultra 7 251HX and Core 3 N355: 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 | 18 (Octadeca-Core) | 8 (Octa-Core) |
| Performance-cores | 6 | no data |
| Efficient-cores | 12 | no data |
| Threads | 18 | 8 |
| Base clock speed | 2.5 GHz | 1.9 GHz |
| Boost clock speed | 5.1 GHz | 3.9 GHz |
| L1 cache | no data | 96 KB (per core) |
| L2 cache | 30 MB | 2 MB (shared) |
| L3 cache | 30 MB | 6 MB (shared) |
| Chip lithography | 3 nm | Intel 7 nm |
| Maximum core temperature | no data | 105 °C |
| 64 bit support | + | + |
Compatibility
Information on Core Ultra 7 251HX and Core 3 N355 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 | no data | 1 |
| Socket | FCBGA2114 | FCBGA1264 |
| Power consumption (TDP) | 160 Watt | 15 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Core Ultra 7 251HX and Core 3 N355. You'll probably need this information if you require some particular technology.
| Instruction set extensions | Intel® SSE4.1, Intel® SSE4.2, Intel® AVX2 | Intel® SSE4.1, Intel® SSE4.2, Intel® AVX2 |
| AES-NI | + | + |
| FMA | - | + |
| AVX | - | + |
| Enhanced SpeedStep (EIST) | + | + |
| Speed Shift | + | + |
| Turbo Boost Technology | 2.0 | no data |
| Hyper-Threading Technology | - | - |
| Idle States | + | no data |
| Thermal Monitoring | + | + |
| GPIO | no data | + |
| Turbo Boost Max 3.0 | - | no data |
| Deep Learning Boost | + | - |
| Supported AI Software Frameworks | OpenVINO™, WindowsML, DirectML, ONNX RT, WebNN | - |
Security technologies
Core Ultra 7 251HX and Core 3 N355 technologies aimed at improving security, for example, by protecting against hacks.
| TXT | + | + |
| EDB | + | no data |
| OS Guard | + | + |
Virtualization technologies
Virtual machine speed-up technologies supported by Core Ultra 7 251HX and Core 3 N355 are enumerated here.
| VT-d | + | + |
| VT-x | + | + |
| EPT | + | + |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Core Ultra 7 251HX and Core 3 N355. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR5-6400 | DDR4, DDR5 |
| Maximum memory size | 256 GB | 16 GB |
| Max memory channels | 2 | 1 |
Graphics specifications
General parameters of integrated GPUs, if any.
| Integrated graphics card | Intel® Graphics | Intel® Graphics |
| Quick Sync Video | + | + |
| Graphics max frequency | 1.8 GHz | 1.35 GHz |
| Execution Units | no data | 32 |
Graphics interfaces
Available interfaces and connections of Core Ultra 7 251HX and Core 3 N355 integrated GPUs.
| Number of displays supported | 4 | 3 |
Graphics image quality
Maximum display resolutions supported by Core Ultra 7 251HX and Core 3 N355 integrated GPUs, including resolutions over different interfaces.
| 4K resolution support | no data | + |
| Max resolution over HDMI 1.4 | 4096 x 2304 @ 60Hz (HDMI 2.1 TMDS)7680 x 4320 @ 60Hz (HDMI 2.1 FRL) | 4096 x 2160@60Hz |
| Max resolution over eDP | 3840 x 2400 @ 120Hz | no data |
| Max resolution over DisplayPort | 7680 x 4320 @ 60Hz | 4096 x 2160@60Hz |
Graphics API support
APIs supported by Core Ultra 7 251HX and Core 3 N355 integrated GPUs, sometimes API versions are included.
| DirectX | 12 | 12.1 |
| OpenGL | 4.5 | 4.6 |
Peripherals
Specifications and connection of peripherals supported by Core Ultra 7 251HX and Core 3 N355.
| PCIe version | 5.0 and 4.0 | 3.0 |
| PCI Express lanes | 24 | 9 |
| USB revision | no data | 2.0/3.2 |
Synthetic benchmarks
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.
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. Other than that, Passmark measures multi-core performance.
Pros & cons summary
| Performance score | 27.19 | 5.98 |
| Recency | 1 April 2026 | 7 January 2025 |
| Physical cores | 18 | 8 |
| Threads | 18 | 8 |
| Power consumption (TDP) | 160 Watt | 15 Watt |
Ultra 7 251HX has a 355% higher aggregate performance score, an age advantage of 1 year, and 125% more physical cores and 125% more threads.
3 N355, on the other hand, has 967% lower power consumption.
The Intel Core Ultra 7 251HX is our recommended choice as it beats the Intel Core 3 N355 in performance tests.
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