Intel Core M-5Y31 vs Intel Core 2 Duo SU7300

Intel Core M-5Y31

The Intel Core M-5Y31 is an ULV (ultra-low voltage) dual-core SoC based on the Broadwell architecture launched in late 2014. Thanks to its TDP of just 4.5 W (configurable), the CPU is suited for passively cooled tablets and 2-in-1 notebooks. In addition to two CPU cores with Hyper-Threading clocked at 0.9 - 2.4 GHz, the chip also integrates an HD Graphics 5300 GPU and a dual-channel LPDDR3/DDR3L(-RS) memory controller up to 25.6 GB/s. The chip is manufactured in a 14 nm process with FinFET transistors.

Using the "configurable TDP" feature, the 5Y31 can be clocked at 1.1 GHz base clock at a higher TDP (it seems like Apple is using this feature in the base model of the 12-inch MacBook Retina 2015).

Architecture

Broadwell represents the "Tick" in Intel's Tick-Tock model, which means a shrink of its predecessor Haswell. The new 14 nm manufacturing process with three-dimensional FinFET transistors allows not only improvements in energy efficiency, but also a significantly smaller die size fit for more compact packages and devices.

Further advantages result from the revised microarchitecture of Broadwell. Due to its improved branch prediction, bigger buffer sizes (1500 instead of 1000 entries in the L2 TLB) and other tweaks, the performance per clock has been increased by more than 5 percent over its predecessor. There are also some new instruction set extensions designed for cryptographic applications.

Performance 

The Core M-5Y31 offers a very wide turbo range from 0.9 - 2.4 GHz. However, the actual frequency is largely limited by the TDP. While the CPU is similar to a Core i5-4200U (Haswell, 15 W) in short benchmarks, its performance will begin to degrade under continuous full load. Accordingly, the main purpose of Broadwell's higher power efficiency is to reduce power consumption instead of improving raw performance.

Overall, the Core M-5Y31 will be sufficient for office and multimedia purposes as well as more demanding applications.

Graphics

The integrated HD Graphics 5300 offers 24 Execution Units (EUs) clocked at 300 - 850 MHz. Similar to the CPU core, the GPU architecture (Intel Gen 8) has been thoroughly revised for improved performance-per-clock. However, the GPU frequency will be also limited by the TDP, which prevents significant performance boosts over the older HD 4200 under continuous 3D load. Current games as of 2014/2015 will be playable in lowest settings only.

Broadwell is the first Intel chip to fully support DirectX 11.2 as well as OpenCL 1.3/2.0 and OpenGL 4.3. Video will output natively via DisplayPort 1.2 or HDMI 1.4a. However, the new HDMI 2.0 standard is not officially supported.

Power Consumption

With a TDP of only 4.5 W, the Core M-5Y31 draws noticeably less power than the Haswell Y-series (11.5 W). However, the TDP can be set to different values such as 3.5 or 6 W, affecting clock rates and performance (6 W: 1.1 GHz base clock, 3.5 W: 0.6 GHz base clock). The CPU can be passively cooled even in thin tablets.

Intel Core 2 Duo SU7300

The Intel Core 2 Duo SU7300 is a CULV laptop processor for small and light laptops. Due to the small clock speed, the CPU is specified with a TDP of only 10 Watt. For non demanding tasks, the performance of both cores is sufficient. Many laptops with the SU7300 feature an overclocking option to run the CPU at higher clock rates (e.g. 1.7 GHz in the Asus UL series). Compared to the Atom series, the SU7300 is signifantly faster.