The Intel Core Ultra 7 255H is a mobile high-end CPU for larger notebooks based on the Arrow Lake architecture. It offers 16 cores consisting of 6 fast performance cores (Lion Cove) with up to 5.1 GHz and 8 smaller efficiency cores (Skymont) with up to 4.4 GHz clock speed and two additional "low power" efficiency cores with up to 2.5 GHz (Skymont). The CPU has access to 24 MB of cache and is specified with a TDP of 28 watt (PL1, 115W PL2).
The SoC integrates a small dedicated NPU called AI Boost with 13 TOPS (Int8) and optionally supports vPro Essentials. The integrated memory controller supports up to 192 GB LPDDR5/x-8400 or DDR5-6400 (dual channel). The integrated GPU (iGPU) is an Intel Arc 140T graphics card which offers eight Xe cores with up to 2.25 GHz.
Performance - High End
The Core Ultra 7 is superior to the top model Core Ultra 9 285H as only the maximum Turbo frequency is 200 MHz lower. Due to the improved IPC of the cores (especially the efficiency cores), the CPU should perform slightly below the level of the old Raptor Lake Core Core 9 270H (6 + 8 cores, max 5.8 / 4.1 GHz). This makes the CPU very suitable for demanding tasks such as high-end gaming and content creation.
Chiplet design
Like the desktop and HX chips, the Arrow Lake-H chips are based on individual chiplets that are placed on a 22nm base tile from Intel using Foveros 3D packaging. The CPU part comes from TSMC using the modern N3B (3nm) process. As with HX, the GPU also is produced at TSMC and is manufactured using the N5P process. SoC and I/O Tile are also from TSMC but in the older N6 process.
The AMD Ryzen 7 8745HX is a higher-end octa-core Dragon Range refresh lineup processor that debuted in April 2025 and is primarily targeted at gaming laptops. This is essentially a rebadged Ryzen 7 7745HX; as such, the product offers 8 SMT-enabled Zen 4 cores (16 threads) running at 3.6 GHz to 5.1 GHz, along with a rather basic Radeon 610M RDNA 2 architecture iGPU.
This Ryzen 7 8000 APU is composed of two dies made on two different nodes (5 nm for CPU cores; 6 nm for other componentry). It features a very healthy 28 PCIe 5 lanes for connecting graphics cards and SSDs as fast as 15.75 GB/s. The RAM controller is limited to DDR5-5200 or slower; there is no NPU and no Thunderbolt support, the product page on amd.com indicates, but the clock multiplier is unlocked for easy overclocking.
Performance
While we have not tested a single system featuring the 8745HX as of April 2025, multi-threaded Cinebench benchmarks put the 7745HX in the same ballpark as the Core Ultra 9 285H, Core Ultra 9 185H and Core i5-13500HX which is fast enough for any 2025 game.
Power consumption
Much like the 7745HX, the 8745HX has a base TDP (long-term power limit) of 55 watts that can officially be jacked up to as high as 75 watts. That's precisely what Minisforum did with only 7745HX system Notebookcheck has tested so far. Either way, to dissipate 50+ watts, at least one high-RPM fan is needed.
Average Benchmarks Intel Core Ultra 7 255H → 0%n=0
- Range of benchmark values for this graphics card - Average benchmark values for this graphics card * Smaller numbers mean a higher performance 1 This benchmark is not used for the average calculation
v1.33
log 13. 03:05:16
#0 ran 0s before starting gpusingle class +0s ... 0s
#1 checking url part for id 18903 +0s ... 0s
#2 checking url part for id 19597 +0s ... 0s
#3 redirected to Ajax server, took 1755047116s time from redirect:0 +0s ... 0s
#4 did not recreate cache, as it is less than 5 days old! Created at Sun, 10 Aug 2025 05:18:26 +0200 +0s ... 0s
#5 composed specs +0.006s ... 0.006s
#6 did output specs +0s ... 0.006s
#7 getting avg benchmarks for device 18903 +0.004s ... 0.01s
#8 got single benchmarks 18903 +0.013s ... 0.022s
#9 getting avg benchmarks for device 19597 +0.001s ... 0.023s
#10 got single benchmarks 19597 +0s ... 0.023s
#11 got avg benchmarks for devices +0s ... 0.023s
#12 min, max, avg, median took s +0.034s ... 0.057s
- Average benchmark values for this graphics card
