Intel Core i7-3687U vs Intel Core i3-1120G4 vs Intel Core i7-3635QM

Intel Core i7-3687U

The Intel Core i7-3687U is the fastest ULV-processor for laptops based on the Ivy Bridge architecture at the time of introduction in Q1 2013. Due to Hyperthreading, the two cores can handle up to four threads in parallel leading to better utilization of the CPU. Each core offers a base speed of 2.1 GHz but can dynamically increase clock rates with Turbo Boost up to 3.1 GHz (for 2 active cores) and 3.3 GHz (for 1 active core). As its Sandy-Bridge-based predecessors, it offers a 4 MB L3-Cache.

Ivy Bridge is an enhanced die shrink of the Sandy Bridge architecture with improvements on both GPU and CPU performance. The CPUs are produced in 22nm (versus 32nm Sandy Bridge CPUs) and are the first to introduce 3D transistors for increased energy efficiency when compared to similarly clocked Sandy Bridge processors. Other new features are integrated PCI Express 3.0 and  DDR3(L)-1600 support.

The performance of the Core i7-3687U is slightly above a similarly clocked Sandy Bridge processor due to the architectural improvements. Therefore, and because of the higher clock speed, the old Core i7-2677M is easily outperformed.

The integrated Intel HD Graphics 4000 offers 16 Execution Units (EUs) clocked at 350 MHz up to 1200 MHz with Turbo Boost, delivering a performance comparable with an AMD Radeon HD 6620G.

The ULV-CPUs are rated at a TDP of 17 W including graphics card and memory controller.  Therefore, the CPU is suited for small laptops and ultrabooks.

Intel Core i3-1120G4

The Intel Core i3-1120G4 is a power-efficient quad-core SoC for laptops and Ultrabooks based on the Tiger Lake-U generation (UP4) that was introduced in September 2020. It integrates four Willow Cove processor cores (8 threads thanks to Hyper-Threading). Each core can clock from 1.1 GHz (base speed) to 3.5 GHz (1 core boost). All cores at once can clock at up to 3 GHz.

Another novelty is the integrated Xe graphics adapter based on the completely new Gen 12 architecture. The i3 integrates the low end UHD Graphics G4 with 48 of the 96 EUs enabled and a clock speed of 400 - 1100 MHz. The GPU and CPU can together use the 8 MB of L3 cache.

Furthermore, Tiger Lake SoCs add PCIe 4 support (4 lanes), AI hardware acceleration, and the partial integration of Thunderbolt 4 / USB 4 and Wi-Fi 6 in the chip.

Performance

While we have not tested a single system built around the 1120G4 as of August 2023, it's fair to expect the chip to be about half as fast as the Core i5-1125G4 (Tiger Lake, 4 cores, 8 threads, up to 3.7 GHz), as far as multi-thread benchmarks are concerned. The 1120G4's low TDP target is slated to limit the chip's real-world Boost clock speeds significantly leading to underwhelming performance and high DPC latencies.

Power consumption

This Core i3 has a default TDP of 7 W to 15 W, the expectation being that laptop manufacturers will go for a higher value in exchange for higher performance. The CPU is built with Intel's third-gen 10 nm process marketed as SuperFin for decent, as of late 2022, energy efficiency.

Intel Core i7-3635QM

The Intel Core i7-3635QM is a fast quad-core processor for laptops based on the Ivy Bridge architecture. Due to Hyperthreading, the four cores can handle up to eight threads in parallel leading to better utilization of the CPU. Each core offers a base speed of 2.4 GHz but can dynamically increase clock rates with Turbo Boost up to 3.2 GHz (for 4 active cores), 3.3 GHz (for 2 active cores) and 3.4 GHz (for 1 active core). In contrast to the 3630QM, the 3635QM has a different package (BGA) and a slightly higher GPU clock.

Ivy Bridge is an enhanced die shrink of the Sandy Bridge architecture with improvements on both GPU and CPU performance. The CPUs are produced in 22nm (versus 32nm Sandy Bridge CPUs) and are the first to introduce 3D transistors for increased energy efficiency when compared to similarly clocked Sandy Bridge processors. Other new features are integrated PCI Express 3.0 and  DDR3(L)-1600 support.

The performance of the Core i7-3635QM is slightly above a similarly clocked Sandy Bridge processor due to slight architectural improvements. As a result, overall performance is similar to the fastest Sandy Bridge model, the Core i7-2960XM.

The integrated Intel HD Graphics 4000 offers 16 Execution Units (EUs) clocked at 650 MHz up to 1200 MHz with Turbo Boost, making it one of the faster variants.

As with most quad-core Ivy Bridge models, the Core i7-3635QM is specified at a TDP of 45 Watts including graphics card and memory controller. Therefore, the CPU is well-suited for laptops 15-inches or greater.