Intel Core i5-1235U vs Intel Core i7-1280P

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.

Intel Core i7-1280P

The Intel Core i7-1280P is the flagship Alder Lake-P CPU, which is to say, an expensive 28 W part meant for use in ultra-light (yet actively cooled) laptops. This CPU was announced in early 2022 and it has 6 performance cores (P-cores, Golden Cove architecture) mated to 8 efficient cores (E-cores, Gracemont architecture). The P-cores are Hyper-Threading-enabled for whopping 20 threads when combined with the E-cores. The clock speeds range from 1.8 GHz to 4.8 GHz for the performance cluster and 1.3 GHz to 3.6 GHz for the efficiency cluster. This is the only hexa-core 28 W Alder Lake CPU as of February 2022, trumping what the more affordable i7-1270P and i7-1260P have in store. Full vPro feature set is supported by this Core i7 ("Enterprise" tier, allowing for remote device management).

Architecture

The i7 is a continuation of Intel's efforts to use the ARM-developed big.LITTLE technology for its own benefit. A single "little" Alder Lake core is supposed to be just as fast as a Skylake core (as found in the venerable Core i7-6700HQ among other options) which is six years old at this point. All of a Core i7-1280P's CPU cores enjoy access to 24 MB of L3 cache. The integrated memory controller supports up to 64 GB of LPDDR5-5200, DDR5-4800, LPDDR4x-4267 or DDR4-3200 RAM. Just like the other 12th Gen Intel Core processors, Core i7-1280P comes with Thread Director which is a new functionality designed to help Windows 11 decide which cores to use for what workload for best performance and efficiency possible. Hardware acceleration of AI algorithms is supported via GNA 3.0 and DL Boost (via AVX2). PCI-Express 5.0 support has not found its way into Alder Lake P processors, so users will have to be content with PCI-Express 4.0 for the time being. Four PCI-Express 4 lanes allow for a read/write rate of up to 7.9 GB/s, provided a suitably fast NVMe SSD is used.

Please note this is not a user-replaceable CPU. It gets soldered permanently on to the motherboard (BGA1744 socket interface).

Performance

The average 1280P in our database delivers multi-thread benchmarks scores that are most similar to those of the Ryzen 9 5900HS, Ryzen 9 PRO 6950HS and also the Core i9-11980HK.

Thanks to its decent cooling solution and a long-term CPU power limit of 80 W, the MSI Summit E16 Flip A12UDT-031 is among the fastest laptops built around the 1280P that we know of. It can be roughly 60% faster in CPU-bound workloads than the slowest system featuring the same chip in our database, as of August 2023.

Graphics

The built-in graphics adapter in the form of the 96 EU Iris Xe running at up to 1.45 GHz has seen no change from what was built into the 11th Gen Tiger Lake-UP3 processors, like a i7-1165G7, which is hardly a downside as this iGPU is loaded with modern features such as AV1 video decoding capability and SUHD 4320p monitor support. An Iris Xe Graphics G7 will let you use up to 4 monitors simultaneously, provided the laptop has the ports required.

The graphics adapter will let you play most games at 1080p / Medium settings to be very close to NVIDIA's MX350.

That being said, the Xe's gaming performance is bound to be tied to how high the Power Limits and how competent the cooling solution of a laptop are. Fast RAM is a prerequisite for decent performance as well (the Iris Xe has to make do with no dedicated video memory).

Last but not the least, we discovered that the GPU utilization when playing YouTube UHD 2160p60 videos is higher than it was with Tiger Lake chips.

Power consumption

The i7's base power consumption (also known as the default TDP value or the PL1) is 28 W, with 64 W being its maximum Intel-recommended Turbo power consumption (also known as the PL2). The "Minimum Assured" power consumption is fairly high at 20 watts. All in all, an active cooling solution is a must for a CPU like this.

The i7-1280P is built with Intel's fourth-gen 10 nm process marketed as Intel 7 for decent, as of late 2022, energy efficiency. This is still a rather power-hungry CPU; a single P-core will happily eat more than 20 W and even ask for more when under heavy load. A couple of higher-end 7 nm U-class AMD Ryzen 5000 chips are noticeably more modest than the i7 while delivering the same or higher performance levels.