Intel Core Ultra 7 155H vs Intel Core Ultra 7 255U

Intel Core Ultra 7 155H

The Intel Core Ultra 7 155H is a high-end laptop processor of the Meteor Lake series that has 16 cores (6 + 8 + 2) and 22 threads at its disposal. This 1st Gen Core Ultra chip has come to replace 13th generation Core chips; its 16 cores are comprised of 6 HT-enabled Performance cores running at up to 4.8 GHz and 10 Efficient cores (8 main cores plus 2 extra ones found in the Low Power Island) running at up to 3.8 GHz.

The 8-core Arc GPU, just out of the oven, serves as the integrated graphics adapter - this runs at up to 2.30 GHz - and there is a bevy of other brand-new technologies on offer as well, including the integrated AI Boost NPU with two Gen 3 engines for hardware AI workload acceleration.

Architecture and Features

With Meteor Lake, Intel intends to deliver higher CPU performance, higher GPU performance and at the same time, longer battery life than what Raptor Lake chips were capable of. The company also wants a large piece of the AI cake and is working with Microsoft and other partners to make that happen. As a result, Windows Defender is now AI-enabled, meaning it can use the Intel NPU to take some of the load off the main CPU cores. We also get this new Intel Device Discovery technology that is designed to give us a better hardware-based remote laptop management than ever before; and, to make things even better, Intel now offers a dedicated Arc Pro graphics driver for workstations.

This generation of Intel Core processors features Redwood architecture P-cores and Crestmont architecture E-cores. Both come with slight architectural improvements over Raptor Cove and Gracemont respectively for slightly higher performance-per-clock figures; the interesting thing is that of the 10 E-cores, two are actually a separate cluster located on what Intel calls a "Low Power Island". Essentially, the latter is an SoC within an SoC that can stay active while most other parts of the chip are temporarily switched off to save power. The low-power E-cores run at up to 2.5 GHz. Intel hopes this approach will let it deliver unprecedentedly low power consumption figures when under low load, boosting battery life of laptops and tablets powered by Meteor Lake.

To build its Meteor Lake processors, Intel uses the Foveros technology (stacking several chips on top of each other). This is a cost-cutting measure more than anything else, as manufacturing several small dies on several different processes is so much cheaper than making a huge single die and hoping that there are no defects in it that will require disabling some parts of it.

Elsewhere, the Core Ultra 7 155H comes with 24 MB of L3 cache and a very healthy number of PCIe 5 and PCIe 4 lanes for NVMe SSD speeds up to 15.7 GB/s. It supports RAM running at up to 7467 MHz (DDR5-5600, LPDDR5-7467, LPDDR5x-7467, to be specific - which is about as good as what 8040 series Ryzen chips have). Naturally, the chip features built-in Thunderbolt 4 support and Intel CNVi Wi-Fi support; fascinatingly enough, Intel chose to keep native SATA III support that AMD had removed from its Ryzen processors quite a while ago.

The 155H is compatible with 64-bit Windows 10, 64-bit Windows 11 and with many Linux distros.

Performance

If one chooses to trust the official performance data published by Intel, then the 155H is about as fast as the Ryzen 9 6900HX (Zen 3 Plus, 8 cores, 16 threads, up to 4.9 GHz), as far as multi-thread performance is concerned. This isn't a ground-breaking result but let's just wait for our in-house testing results instead of jumping to conclusions.

Either way, real-world performance of the chip may vary significantly depending on how high the CPU power limits are and how competent the cooling solution of the system is.

Graphics

The 8-core Arc GPU running at up to 2.30 GHz is slated to be a proper alternative to the mighty Radeon 780M. The thing is almost as fast as the GTX 1650 (Laptop) and the RTX 2050 (Laptop) to represent some seriously solid performance gains over aging Xe-series integrated GPUs. If one chooses to take Intel's word for it, that is.

A proper DX12 Ultimate graphics adapter, the Arc is no stranger to ray tracing and other modern technologies including AI frame generation (XeSS). It will let you connect up to four SUHD 4320p monitors and it will both HW-encode and HW-encode the most widely used video codecs including AVC, HEVC and AV1 in a fast and efficient manner.

Your mileage may vary depending on how high the CPU power limits are, how competent the cooling solution of your system is, how fast the RAM of your system is. The latter is really important; Intel stresses that for the Arc to deliver the best results possible, multi-channel RAM configuration is a must.

Power consumption

This mighty Core Ultra 7 series processor has a Base power consumption of 28 W, while its Turbo power consumption is not supposed to exceed 115 W. Its Base power consumption is supposed to be around 64 W, however, most laptop makers will probably go for a higher value to get higher clock speeds and thus better performance. Either way, a powerful cooling solution will be needed to sort out this chip's hot temper.

The 155H is comprised of five small chips ("tiles") that are connected using Intel's Foveros technology. The tile containing main CPU cores is produced on the fairly modern 7 nm Intel process marketed as Intel 4 while most other tiles (the iGPU, the I/O die, ...) are built with TSMC's N5 and N6 processes. The base tile is built with the old Intel 22FFL process.

Intel Core Ultra 7 255U

The Intel Core Ultra 7 255U is an upper mid-range CPU with 12 cores from the Arrow Lake U series, which was introduced at the beginning of 2025. The chip is similar to the Meteor Lake U series, but the compute part is manufactured using the modern Intel 3 process and therefore offers higher clock rates.

Like its predecessor, the SoC is based on a tile/chiplet design. The smaller compute tile (compared to the H processors) offers 2 performance cores (P cores, Redwood Cove architecture, SMT) and 8 efficiency cores (E cores, Crestmont architecture). The P-cores support hyperthreading (therefore 14 threads together) and clock up to 5.2 GHz. The E-cores clock at a maximum of 4.2 GHz. In addition, there are now two more low-power efficiency cores with up to 2.4 GHz on the low-power island; the compute tile can therefore be completely deactivated when idle and during simple tasks in order to save power.

Performance

Due to the higher clock rates, the Core Ultra 7 255U can clearly distinguish itself from the old top model Core Ultra 7 165U (12 cores, max 4.9 / 3.8 GHz, 12 MB cache). The old Core Ultra 7 155U lags even further behind due to its low clock rates.

Graphics unit

The Core Ultra 7 155U offers a new Arc-based iGPU called Intel Graphics with 4 Xe cores and 64 EUs that reach a maximum of 2.1 GHz. However, the performance is far below the new Arc iGPU in the H series.

Features

Arrow Lake-U has integrated WiFi 6E (WiFi 7 optional). The integrated memory controller now supports LPDDR5/x-8400 or DDR5-6400 (max. 128 GB). A dedicated NPU (2x Gen3 Neural Compute Engines) is now used. The Xe Media Engine supports MPEG-2, AVC, VC-1 Decode, JPEG, VP8 Decode, VP9, HEVC and AV1 Decode up to 8K 10-bit HDR. The chip now supports PCIe-5.0 (x8 for GPU) and PCIe-4.0 (three x12 for SSDs).

Power consumption

The Intel Core Ultra 7 255U is specified with 15 watts TDP (base) and 57 watts (PL2) max. turbo power. Meteor Lake consists of five individual chips, whereby the processor part is manufactured in the new Intel 3 process (5nm). The graphics unit is produced at TSMC in N5 and the SoC and I/O tile in the older N6 process. These 4 chips are then applied to the 22nm base tile using the Foveros process.