Intel Core i7-1255U vs Intel Core i5-10310U vs Intel Core i5-1230U

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.

Intel Core i5-10310U

The Intel Core i5-10310U is a power efficient quad-core SoC for notebooks based on the Comet Lake (CML-U) generation and was announced in August 2019. Compared to the similar Whiskey Lake processors (e.g. Core i5-8665U), the only difference is support for higher memory speeds (DDR4-2666 vs 2400) and two additional cores in the top model (not in this i5). The processor cores are clocked between 1.7 and 4.4 GHz (unverified). Thanks to HyperThreading 8 threads can be used. Compared to the faster i5-10510U, the level 3 cache was reduced from 8 to 6 MB. More information on Comet Lake and all the models and articles on it can be found here. The CPU supports the professional management features under the vPro umbrella.

The integrated graphics adapter however is still the same as in the previous generations. It should be still called Intel HD Graphics 620 and clock from 300 - 1100 MHz in the i5. Furthermore, the SoC integrates a VP9 and H.265 de- and encoder and an integrated dual channel DDR4-2666 / LPDDR4x 2933 / LPDDR3-2133 memory controller.

Performance

The average 10310U in our database is not really any different than other quad-core laptop CPUs running at similar clock speeds, such as the Ryzen 5 3450U or the Core i5-1035G4.

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

Power consumption

This Core i5 has a default TDP (also known as the long-term power limit) of 15 W, a value that laptop manufacturers are free to change to anything between 10 W and 25 W with clock speeds and performance changing correspondingly. Perhaps more importantly, short-term power consumption can be as high as 80 W or even 90 W as far as 10th gen Comet Lake U chips are concerned, making passively cooled designs unlikely.

This Intel processor is manufactured on a fairly old, as of late 2022, 14 nm Intel process for subpar energy efficiency.

Intel Core i5-1230U

The Intel Core i5-1230U is a 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 to 4.4 GHz on the performance cluster and 0.7 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 12 MB L3 cache.  Compared to the similar Core i5-1240U, the 1230U offers a lower base CPU clock speed and only "Essentials" vPro management features.

Performance

Compared to the old 7 Watt Comet Lake-Y series (like the i7-10510Y), the performance should be clearly better thanks to the 10 cores and the improved architecture of the P-cores. Compared to the 15 W U-series (like the similar specified Core i5-1235U) the sustained performance will be clearly limited by the 9 Watt TDP. As always, the performance will also greatly depend on the cooling solution, especially for fanless laptops and tablets.

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 80 of the 96 EUs (Execution Units) operating at up to 0.85 GHz.

The CPU is rated at 9 W base power (TDP, PL1) and 29 W max. Turbo power (PL2) and the whole SoC is manufactured on a 10nm process at Intel, which is known as Intel 7.