Intel Core i5-1240U vs Intel Core i5-8400H

Intel Core i5-1240U

The Intel Core i5-1240U 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 1.1 to 4.4 GHz on the performance cluster and 0.8 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 i7-1260U, the 1240U offers lower clocked CPU cores, a slower iGPU, but the same "Enterprise" 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 i5-1245U) 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 0.9 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.

Intel Core i5-8400H

The Intel Core i5-8400H is a high-end processor for laptops with four cores based on the Coffee Lake architecture and will be announced early 2018. The processor clocks at between 2.5 and 4.2 GHz (4.1 with 4 cores) and can execute up to eight threads simultaneously thanks to Hyper-Threading. According to Intel, the CPU is manufactured in an improved 14nm (14nm++) process.

The Coffee Lake architecture is similar to Kaby Lake and differs only in the amount of cores (now six cores for the high end versions) and the improved 14nm process (14nm++ according to Intel).

Performance

The Intel Core i5-8400H should perform similar as the older Core i7-7920HQ (3.1 - 4.1 GHz). The faster Coffee Lake CPUs, like the Core i7-8750H offers two additional cores and is therefore up to 50% faster in multithreaded benchmarks. Still, the performance of the i5-8400H should be sufficient for even demanding applications and games.

Graphics

The integrated Intel UHD Graphics 630 iGPU is supposed to offer a slightly higher performance as its clock rate has been increased by 50 MHz (rumored). The architecture is identical to that of the Intel HD Graphics 630. We do expect a performance improvement, but as a low-end solution it will probably only display current games smoothly at reduced details - if at all.

Power Consumption

Intel specifies the TDP with 45 watts and therefore the i5 is only suited for big laptops with good cooling solutions. Using cTDP-down, the CPU can also be configured to 35 Watt resulting in a reduced performance.