Intel® Core™ Ultra 7 255HX

The Intel Core Ultra 7 255HX is a laptop processor with a hybrid 20-core layout (8 performance cores + 12 efficiency cores) and 20 threads, built on the Arrow Lake architecture. It launched in Jan 2025. Clocks run from 2.4 GHz base to 5.2 GHz boost. A 30-MB L3 cache backs the cores (3.4 MB per core). It addresses DDR5 memory up to 256 GB across 2 channels. The chip drops into the FCBGA2114 socket and exposes PCIe 5.0 (24 lanes). Rated TDP is 55 W. Notable platform capabilities: Gaussian Neural Accelerator, Extended Page Tables (EPT), Control-flow Enforcement (CET).

The Intel Core Ultra 7 255HX scores 4,576 in single-core performance and 48,833 in multi-core performance (PassMark CPU Mark ratings). From those two ratings Feex computes 14,949 for overall performance, 38,148 for productivity performance, 35,095 for creator performance, 59,210 for engineering performance and 25,936 for gaming performance. Its multi-core throughput works out to 2,442 per core, 2,442 per thread and 888 per watt. Its computed efficiency index is 2,016. Its performance index is 185, so its overall performance is 85% above the Intel Core i5-12400 (index 100). Each bar shows the score as a share of a reference ceiling, which is the larger of the 99th-percentile score across the Feex CPU database and a fixed baseline.

Scores for individual PassMark CPU Mark test categories. Higher is better. These are measured test scores, not computed from the single-core and multi-core ratings.

In the individual workload tests the Intel Core Ultra 7 255HX scores 127,543 in integer math, 161,217 in floating-point math, 516,868 in compression, 39,648 in cryptography, 2,943 in physics simulation, 41,376 in vector SIMD, 401 in the prime sieve and 62,800 in sorting. Higher is better. Compared with the Intel Core i5-12400, it is 117% above in integer math, 251% above in floating-point math, 127% above in compression, 245% above in cryptography, 170% above in physics simulation, 167% above in vector SIMD, 499% above in the prime sieve and 177% above in sorting. Each bar shows the score as a share of that workload's reference ceiling, the larger of the 99th-percentile score across CPUs with a recorded value and a fixed baseline.

The Intel Core Ultra 7 255HX has 20 physical cores and runs 20 logical threads. It uses a hybrid layout of 8 performance cores and 12 efficiency cores. It does not support simultaneous multithreading, so its thread count equals its core count. It runs at a base clock of 2.40 GHz and boosts up to 5.20 GHz.

The Intel Core Ultra 7 255HX is a laptop processor, belongs to the Intel Core Ultra 7 family, uses the Arrow Lake architecture, carries the codename Arrow Lake and is manufactured on a 3 nm process. It launched in Jan 2025.

The Intel Core Ultra 7 255HX has 2 MB of L1 cache, 36 MB of L2 cache and 30 MB of L3 cache. That adds up to about 68.0 MB of cache, or 3.40 MB per core.

The Intel Core Ultra 7 255HX has a 3-level cache hierarchy: L1 at 2 MB, L2 at 36 MB and L3 at 30 MB. L2 is the largest level and makes up about 53% of the cache listed here.

The Intel Core Ultra 7 255HX supports DDR5 memory, addresses up to 256 GB of memory, uses 2 memory channels, runs memory at up to 7,200 MT/s and delivers up to 115.2 GB/s of memory bandwidth. It does not support DDR4 and LPDDR memory. It does not support ECC memory.

The Intel Core Ultra 7 255HX includes integrated graphics (Intel Graphics) and clocks the graphics up to 1.85 GHz.

The Intel Core Ultra 7 255HX uses the FCBGA2114 socket, supports PCI Express 5.0 and provides up to 24 PCIe lanes.

The Intel Core Ultra 7 255HX has a rated TDP of 55 W.

Instruction sets, security, virtualization, AI acceleration and OS readiness. Features are listed as supported, explicitly not supported, or not recorded; a feature that is not recorded is not the same as unsupported.

The Intel Core Ultra 7 255HX is also identified by the model number 255HX and the processor number 255HX.

Feex has recorded 67% of the specifications it tracks for the Intel Core Ultra 7 255HX. Values Feex does not hold are shown as "Not recorded" rather than estimated.

Not recorded: Core Configuration: All-Core Boost and Unlocked Multiplier. Architecture & Generation: ISA Family and Market Status. Cache: L2 Cache (per Core) and L4 Cache. Graphics: Execution Units, Display Outputs and Max Video Memory. Platform & Compatibility: Package and Package Size. Power & Thermals: Base Power, Maximum Turbo Power, Configurable TDP (Min), Configurable TDP (Max), Max Junction Temperature and Tcase. Physical & Manufacturing: Transistor Count, Die Size, Die Count, Foundry and Launch Price. Naming & Aliases: SKU and Part Number.

Processors that use the same FCBGA2114 socket as the Intel Core Ultra 7 255HX and have the closest multi-core scores in the Feex database include Intel Core Ultra 7 270HX+, Intel Core Ultra 7 265HX, Intel Core Ultra 7 251HX, Intel Core Ultra 9 275HX and Intel Core Ultra 5 235HX.