AMD Ryzen 7 5825U vs Intel Core i7-1255U

AMD Ryzen 7 5825U

The AMD Ryzen 7 5825U is a processor for thin and light laptops based on the Cezanne generation. It is part of the "Barcelo" refresh in early 2022 and offers 100 MHz higher clocked CPU cores compared to the old Ryzen 7 5800U. The R7 5825U integrates all eight cores based on the Zen 3 microarchitecture and is the fastest U-series processor at launch. They are clocked at 2 (guaranteed base clock) to 4.5 GHz (Turbo) and support SMT / Hyperthreading (16 threads). The chip is manufactured on the modern 7 nm TSMC process.

The new Zen 3 microarchitecture offers a significantly higher IPC (instructions per clock) compared to Zen 2. For desktop processors AMD claims 19 percent on average and in applications reviews showed around 12% gains at the same clock speed.

Performance

The average 5825U in our database is in the same league as the Ryzen 7 7735U and the Core i7-1270P, as far as multi-thread benchmark scores are concerned. Which is a really good result, as of early 2023.

Thanks to its decent cooling solution and a long-term CPU power limit of 37 W, the 2022 Envy x360 15 is among the fastest laptops built around the 5825U that we know of. It can be more than 15% faster in CPU-bound workloads than the slowest system featuring the same chip in our database, as of August 2023.

In addition to the eight CPU cores, the APU also integrates a Radeon RX Vega 8 GPU with 8 CUs at up to 2000 MHz. The dual channel memory controller supports DDR4-3200 and energy efficient LPDDR4-4266 RAM. Furthermore, 16 MB level 3 cache (up from 8 MB at the 4800U) can be found on the chip.

The TDP of the APU is specified at 15 Watt (default) and can be configured from 10 to 25 Watt by the laptop vendor (most chips are configured higher than 15 Watt). That means the chip is intended for thin and light laptops (but with fans).

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.