AMD Ryzen 9 8945H vs Intel Core i3-1215U vs Intel Core i7-1255U

AMD Ryzen 9 8945H

The Ryzen 9 8945H is a rebadged Ryzen 9 7940HS with higher clock speeds on the Ryzen AI NPU. To be more specific, this is a powerful Hawk Point family laptop chip that has eight Zen 4 cores running at 4.0 GHz to 5.2 GHz. All of its cores are SMT-enabled for a total of 16 processing threads.

Compared to the 8945HS, the H seems to be a local variant for China and offers the same specifications.

The Radeon 780M serves as the integrated graphics adapter.

Architecture & Features

Hawk Point family chips are powered by the Zen 4 architecture, much like Phoenix and Dragon Range family chips are. That's not to say there is no difference between the three. With Hawk Point, AMD is betting big on generative AI; these chips are promised to deliver an up to 40% increase in generative AI performance over 7040 series APUs making apps like DaVinci Resolve and Adobe Photoshop even more powerful.

Unlike Zen 3, Zen 4 features AVX512 support and, thanks to a plethora of other improvements including larger caches/registers/buffers across the board, is slated to bring a double-digit IPC improvement over the former.

Elsewhere, the 8945H has 16 MB of L3 cache and support for super-fast RAM (up to LPDDR5x-7500 or DDR5-5600; no ECC support). The processor is compatible with USB 4 and thus with Thunderbolt; PCIe support is limited to the 4.0 spec for a throughput of 1.97 GB/s per lane. 20 lanes are available.

OS support is limited to 64-bit editions of Windows 11 and Windows 10 and of course to Linux. Note that the chip isn't overclockable and neither is it user-replaceable as it gets soldered down for good (FP7, FP7r2, FP8 socket interfaces).

Performance

The 8945H is an R9 7940HS in disguise, so it's realistic to expect the chip to be just slightly faster than the Core i9-12900HK and also the Ryzen 7 7840HS, as far as multi-thread performance is concerned.

Your mileage may vary depending on how high the CPU power limits are and how competent the cooling solution of your system is.

Graphics

The Radeon 780M has 12 CUs (768 shaders) running at up to 2,800 MHz. This is a very fast iGPU, as of late 2023. It will let you use up to 4 monitors with resolutions as high as SUHD 4320p, and it is also capable of HW-encoding and HW-decoding the most widely used video codecs including AVC, HEVC and AV1. More importantly, it is fast enough for proper 1080p gaming as long as one is fine with low to medium detail settings.

Your mileage may vary depending on how high the CPU power limits are, how competent the cooling solution of the system is, how fast the RAM of the system is (there is no dedicated VRAM here).

Power consumption

This Ryzen 9 series chip has a long-term power limit (default TDP) of 35 W to 54 W, giving laptop makers a choice between longer battery life and higher performance. Either way, an active cooling solution is a must for a system powered by this chip.

The 8945H is built with TSMC's 4 nm process for high, as of late 2023, energy efficiency.

Intel Core i3-1215U

The Intel Core i3-1215U is a mid-range mobile CPU for thin and light laptops based on the Alder Lake architecture. It was announced in early 2022 and offers 2 performance cores (P-cores, Golden Cove architecture) and 4 efficient cores (E-cores, Gracemont architecture). The P-cores support Hyper-Threading leading to 8 supported threads when combined with the E-cores. The clock rate ranges from 1.2 to 4.4 GHz on the performance cluster and 0.9 to 3.3 GHz on the efficient cluster. The performance of the E-cores should be similar to old Skylake cores (compare to the Core i7-6700HQ). All cores can use up to 10 MB L3-cache. Compared to the faster i5 and i7 models, the i3 does not include vPro features.

Performance

The average 1215U in our database is in the same league as the Ryzen 3 5300U and also the Core i7-1185G7, as far as multi-thread benchmark scores are concerned. This is decent enough of a result, as of late 2022. For an entry-level CPU, that is.

Your mileage may vary depending on how competent the cooling solution of your laptop is, and how high the CPU power limits are.

Features

The integrated memory controller supports various memory types up to DDR5-4800, DDR4-3200, LPDDR5-5200, and LPDDR4x-4267. The Thread Director (in hardware) can support the operating system to decide which thread to use on the performance or efficient cores for the best performance. For AI tasks, the CPU also integrates GNA 3.0 and DL Boost (via AVX2). Quick Sync in version 8 is the same as in the Rocket Lake CPUs and supports MPEG-2, AVC, VC-1 decode, JPEG, VP8 decode, VP9, HEVC, and AV1 decode in hardware. The CPU only supports PCIe 4.0 (x8 for a GPU and two x4 for SSDs).

The integrated graphics card is based on the Xe-architecture and offers 64 of the 96 EUs (Execution Units) operating at up to 1.1 GHz.

The CPU is rated at 15 W base power (TDP, PL1) and 55 W max. Turbo power (PL2) and the whole SoC is manufactured in a 10nm process at Intel, which is known as Intel 7.

Intel Core i7-1255U

The Intel Core i7-1255U is a high-end mobile CPU for thin and light laptops based on the Alder Lake architecture. It was announced in early 2022 and offers 2  performance cores (P-cores, Golden Cove architecture) and 8 efficient cores (E-cores, Gracemont architecture). The P-cores support Hyper-Threading leading to 12 supported threads when combined with the E-cores. The clock rate ranges from 1.7 to 4.7 GHz on the performance cluster and 1.2 to 3.5 GHz on the efficient cluster. The performance of the E-cores should be similar to old Skylake cores (compare to the Core i7-6700HQ). All cores can use up to 12 MB L3 cache. Compared to the i7-1265U (fastest U-series CPU at launch), the 1255 offers 100 MHz lower clocked CPU cores and only "Essentials" vPro management features. Compared to the P-series (28W) or H-series (45W), the 15W TDP may limit the sustained performance.

Performance

The average 1255U in our database is in the same league as the Ryzen 5 5600U, as far as multi-thread benchmark scores are concerned. Which is nothing to be ashamed of, as of mid 2023.

Thanks to its decent cooling solution and a long-term CPU power limit of 28 W, the Spectre x360 13.5 14t-ef000 is among the fastest laptops built around the 1255U that we know of. It can be 20% faster in CPU-bound workloads than the slowest system featuring the same chip in our database, as of August 2023.

Architecture

The integrated memory controller supports various memory types up to DDR5-4800, DDR4-3200, LPDDR5-5200, and LPDDR4x-4267. The Thread Director (in hardware) can support the operating system to decide which thread to use on the performance or efficient cores for the best performance. For AI tasks, the CPU also integrates GNA 3.0 and DL Boost (via AVX2). Quick Sync in version 8 is the same as in the Rocket Lake CPUs and supports MPEG-2, AVC, VC-1 decode, JPEG, VP8 decode, VP9, HEVC, and AV1 decode in hardware. The CPU only supports PCIe 4.0 (x8 for a GPU and two x4 for SSDs).

The integrated graphics card is based on the Xe-architecture and offers all 96 EUs (Execution Units) operating at up to 1.25 GHz.

Power consumption

This Core i7 has a "minimum assured" power consumption of 12 W. Its Base power consumption sits at 15 W and its maximum Intel-recommended Turbo power consumption isn't supposed to exceed 55 W. All those values are too high to allow for pasisvely cooled designs.

Last but not the least, Core i7-1255U is built with Intel's fourth-gen 10 nm process marketed as Intel 7 for decent, as of late 2022, energy efficiency.