Intel Core i5-4258U

The Intel Core i5-4258U is a LV (low voltage) dual-core processor for large ultrabooks launched in Q2 2013. It is based on the Haswell architecture and is manufactured in 22nm. Due to Hyper-Threading, 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 2.4 GHz, but can dynamically increase clock rates with Turbo Boost up to 2.9 GHz for 1 or 2 active cores.

Haswell is the successor to the Ivy Bridge architecture with improvements on both GPU and CPU performance. The CPUs are produced in 22nm and offer an optimized branch prediction as well as additional execution ports, improving the performance per clock by almost 10 percent. Furthermore, new features like AVX2 and FMA should increase the performance in future applications.

Due to these architectural improvements, the performance is slightly above a similarly clocked Ivy Bridge CPU. Therefore, the Core i5-4258U is almost as fast as the older i5-3230M. However, when using new instruction sets such as AVX2 the performance can be significantly better. Thus, the CPU has sufficient power for office and multimedia purposes as well as more demanding applications.

The integrated Iris Graphics 5100 offers 40 Execution Units (EUs) clocked at 200 - 1100 MHz with Turbo Boost, making it significantly faster than the HD Graphics 4000. As a result, the Iris Graphics competes with dedicated lower mid-range graphics cards. However, even fast dual-channel memory limits the performance.

The i5-4258U is rated at a TDP of 28 W including the graphics card, memory controller, VRMs and the integrated chipset. Therefore, the CPU is suited for larger ultrabooks 14-inches or greater.