Intel Core i5-8365U vs Intel Core i5-1235U

Intel Core i5-8365U

The Intel Core i5-8365U is a power efficient quad-core SoC for notebooks and Ultrabooks based on the Whiskey Lake generation and was announced in April 2019 as part of two vPro capable CPUs of the WHL-U series. Compared to the similar named Kaby Lake-R processors (e.g. Core i5-8250U), the Whiskey Lake CPUs are now produced in a further improved 14nm process (14nm++) and offer higher clock speeds. The architecture and features are the same. The i5-8365U offers e.g. high Turbo clock speeds of 4.1 GHz (versus 3.4 GHz of the i5-8250U) for a single core. The integrated GPU is still named Intel UHD Graphics 620 and the dual-channel memory controller still supports the same RAM speeds as Kaby-Lake-R (DDR4-2400 / LPDDR3-2133). Thermal Velocity Boost is not supported (only in the Core i7-8565U).

Compared to the predecessor, the Core i5-8265U, the i5-8365U offers a 200 MHz higher Turbo Boost. As the i5-8365U first appeared in a Thinkpad, the CPU most likely supports vPRO for additional hardware management features.

The Whiskey Lake SoCs are used with a new PCH produced in 14nm that supports USB 3.1 Gen 2 (10 Gbps) and CNVi WiFi/BT parts.

Architecture

Intel basically uses the same micro architecture compared to Skylake and Kaby Lake, so the per-MHz performance does not differ. That means Whiskey Lake is a Kaby Lake chip manufactured in the improved 14nm++ process.

Performance

The performance of the i5-8365U depends on the cooling solution of the laptop and the defined TDP limits for short and long term performance. We already saw big differences for Kaby Lake-R (e.g., i7-8550U benchmarks), especially for long term (sustained) performance. Therefore, it will be interesting to see how the additionalTurbo  clock speed can be made use of. Compared to the Core i5-8265U (see for benchmarks), the 200 MHz higher Turbo Boost should result in some gains in single core benchmarks.

Graphics

The integrated Intel UHD Graphics 620 (Intel Gen 9.5) is untouched from the 8th Gen Kaby Lake chips. With fast dual-channel memory it can reach the performance of a dedicated GeForce 920M.

Contrary to Skylake, Kaby Lake and Whiskey Lake now also supports H.265/HEVC Main 10 with a 10-bit color depth as well as Google's VP9 codec. The dual-core Kaby Lake processors announced in January should also support HDCP 2.2.

Power Consumption

The chip is manufactured in a further improved 14nm process with FinFET transistors (14nm++), the same as the 8th Gen Coffee Lake processors. Intel still specifies the TDP with 15 Watts, which is typical for ULV chips. Depending on the usage scenario, the TDP can vary between 7.5 (cTDP Down) and 25 Watts.

Intel Core i5-1235U

The Intel Core i5-1235U 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 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 1.3 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 12 MB L3 cache. Compared to the i5-1245U, the 1235U offers lower base clock speeds 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 1235U in our database is in the same league as the Ryzen 5 PRO 5650U and also, surprisingly enough, the i7-1250U and the i7-1260U, as far as multi-thread benchmark scores are concerned. This is a very respectable result, as of mid 2023.

Thanks to its decent cooling solution and a long-term CPU power limit of 27 W, the Beelink SEi12 is among the fastest systems built around the 1235U that we know of. It can be twice as fast in CPU-bound workloads as 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 80 of the 96 EUs (Execution Units) operating at up to 1.2 GHz.

Power consumption

This ULV processor has a Base power consumption of 15 W (also known as the long-term power limit), with 55 W being its maximum Intel-recommended Turbo power consumption. Both values are too high to allow for passively cooled designs.

Core i5-1235U is manufactured on Intel's fourth-gen 10 nm process marketed as Intel 7 for decent, as of mid-2022, energy efficiency.