Quick Verdict
A powerhouse mobile CPU offering unlocked overclocking and massive multi-core throughput for desktop replacements.
Overview
Launch
2025
Status
ActiveGeneration
Ultra 7 (Arrow Lake-HX)
Market
Mobile
The Intel Core Ultra 7 255HX is a high-performance mobile processor designed for enthusiast gaming laptops and portable workstations. Launched in early 2025, it is based on the Arrow Lake-HX architecture, featuring a robust 20-core configuration without Hyper-Threading. This setup includes 8 'Lion Cove' P-Cores and 12 'Skymont' E-Cores, operating across 20 threads. Manufactured on TSMC's 3nm process, the chip boasts a die size of 243 mm² and packs 17.8 billion transistors. It reaches impressive clock speeds, with a base frequency of 2.4 GHz and a maximum turbo of 5.2 GHz. The processor features an unlocked multiplier, a rare feature for mobile chips, allowing OEMs and extreme enthusiasts to push performance boundaries. With a base power of 55W and a maximum turbo power of 160W, it delivers desktop-class performance in a mobile form factor, paired with Arc Xe-LPG Graphics 64EU and a 13 TOPS NPU.
Intel's Core Ultra 7 255HX brings desktop-class silicon to mobile devices with 8 Lion Cove P-Cores and 12 Skymont E-Cores. Running at 55W base and 160W turbo, it offers exceptional performance for gaming and rendering. The unlocked multiplier is a standout feature, though its 13 TOPS NPU is relatively modest compared to newer architectures.
Specifications
Performance
Rivals desktop CPUs in multi-threaded workloads like Cinebench and Blender.
Excellent for running multiple VMs locally on a workstation laptop.
Exceptional gaming performance when paired with a high-end discrete GPU, limited only by power constraints.
Low efficiency at idle compared to standard H-series, designed for plugged-in performance.
- •High single-core boost clocks minimize bottlenecks
- •Best paired with RTX 4080/4090 mobile GPUs
- •Not intended for thin-and-light gaming
- •NPU 3 provides 13 TOPS
- •Total platform AI is 33 TOPS
- •Sufficient for basic background AI tasks but not heavy local LLMs
Architecture
3 nm
Process Node
Arrow Lake-HX
Codename
20C / 20T
Core Config
30 MB
L3 Cache
55 W
TDP
Architecture Overview
Arrow Lake-HX represents a significant architectural shift for Intel's mobile lineup, moving away from Hyper-Threading to rely purely on physical cores for multi-threaded workloads. The 'Lion Cove' P-Cores deliver substantial Instructions Per Clock (IPC) improvements, while the 'Skymont' E-Cores offer unmatched throughput per watt, effectively replacing the need for logical threads. The architecture utilizes a disaggregated design, though heavily optimized for high-power mobile segments. It supports dual-channel DDR5 memory at 6400 MT/s, providing up to 102.4 GB/s of bandwidth. For connectivity, it offers 20 PCIe Gen 5 lanes directly from the CPU and 4 Gen 4 lanes, ensuring high-bandwidth pathways for multiple GPUs and fast NVMe storage arrays. The integrated Arc Xe-LPG Graphics with 64 Execution Units handles display outputs and light rendering tasks, while the NPU 3 provides 13 TOPS for basic AI acceleration, though the focus remains heavily on raw CPU and discrete GPU pairing.
CPU Design
8x Lion Cove P-Cores and 12x Skymont E-Cores (No Hyper-Threading).
Memory Subsystem
Dual-channel DDR5-6400.
PCIe & I/O
20 PCIe Gen 5 lanes (CPU) and 4 Gen 4 lanes.
Overclocking
Fully unlocked multiplier for enthusiast tuning.
- Removal of Hyper-Threading for efficiency
- Introduction of Skymont E-Cores
- Integrated NPU for AI tasks
Key Highlights
- Massive 20-core count
- Unlocked multiplier for mobile overclocking
- 20 PCIe Gen 5 lanes
- Excellent 5.2 GHz single-core boost
- Desktop-class performance
- High power consumption (160W turbo)
- Modest 13 TOPS NPU
- Requires massive cooling solution
- Poor battery life in laptops
History
The Core Ultra 7 255HX was introduced as part of Intel's Arrow Lake mobile family in January 2025, following the desktop Arrow Lake-S launch. This release was critical for Intel to re-establish dominance in the enthusiast gaming laptop market, a segment where AMD's Ryzen 7000 and 9000 series had gained significant ground. By bringing desktop-class silicon to the mobile socket (BGA 2114) with an unlocked multiplier, Intel aimed to offer extreme performance for heavy-duty gaming and content creation.
The Arrow Lake architecture also marked Intel's increased reliance on TSMC for leading-edge manufacturing, utilizing the N3B node for the compute tiles. The 255HX specifically filled the gap between the mainstream Core Ultra 7 255H and the flagship Core Ultra 9 models, offering a compelling mix of 20 cores and high turbo frequencies for users who needed desktop replacement performance without sacrificing the integrated graphics fallback.
Improvements over Previous Generation
- Removal of Hyper-Threading for efficiency
- Introduction of Skymont E-Cores
- Integrated NPU for AI tasks
Alternatives & Competitors
Should You Buy It?
Recommended for the right buyer
Desktop replacement gaming laptop
Avoid if…
- You need long battery life
- You primarily use light office applications
Use Cases
Interesting Facts
Features an unlocked multiplier, rare for mobile chips.
Contains 20 physical cores without Hyper-Threading.
Packs 17.8 billion transistors in a 243 mm² die.
Supports up to 20 PCIe Gen 5 lanes.
Base power is 55W with a massive 160W turbo limit.
Uses 'Lion Cove' P-Cores and 'Skymont' E-Cores.
Integrated Arc Xe-LPG Graphics with 64 Execution Units.
Manufactured on TSMC's 3nm process.
Uses B0 Stepping silicon.
Total Int8 TOPS rated at 33 TOPS.
People Also Ask
Is the Core Ultra 7 255HX unlocked?
Yes, it features an unlocked multiplier for overclocking.
Does the 255HX have Hyper-Threading?
No, it uses 20 physical cores (8P+12E) without Hyper-Threading.
What is the turbo power of the 255HX?
The maximum turbo power (PL2) is 160W.
What socket does the 255HX use?
It uses the Intel BGA 2114 socket.
Does the 255HX have an NPU?
Yes, it features NPU 3 with 13 TOPS of performance.
What is the base clock of the 255HX?
The base clock is 2.4 GHz.
How many PCIe lanes does the 255HX have?
It has 20 PCIe Gen 5 lanes and 4 Gen 4 lanes.
Is the 255HX good for gaming?
Yes, it is excellent for high-end gaming when paired with a discrete GPU.
What graphics are integrated into the 255HX?
It includes Arc Xe-LPG Graphics with 64 Execution Units.
When was the Core Ultra 7 255HX released?
It was released on January 13th, 2025.
Frequently Asked Questions
What memory speed does the 255HX support?
It supports DDR5-6400 memory.
Can the 255HX be overclocked on a laptop?
Yes, if the laptop manufacturer provides the BIOS support for the unlocked multiplier.
What is the L3 cache size?
It has 30 MB of shared L3 cache.
Does it support ECC memory?
No, the 255HX does not support ECC memory.
What is the maximum turbo frequency?
The maximum turbo frequency is 5.2 GHz.
What core architectures are used?
It uses Lion Cove P-Cores and Skymont E-Cores.
What is the transistor count?
The chip has 17.8 billion transistors.
What is the base power (PL1)?
The base power is 55W.
Does it feature integrated graphics?
Yes, Arc Xe-LPG Graphics 64EU.
What is the TJMax for the 255HX?
The maximum operating temperature is 105°C.