Intel Core i7-1255U vs Intel Core i5-4400E vs Intel Core i5-4300U

The Intel Core i5-4400E is a dual-core processor for embedded systems launched in mid-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 2.7 GHz, but can dynamically increase clock rates with Turbo Boost up to 3.3 GHz for 1 active core. The memory controller supports ECC.

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.

The performance of the Core i5-4400E is similar to the consumer model Core i5-4300M with a slighty lower base clock. Therefore, the 4400E should be comparable to the Ivy Bridge based Core i7-3520M.

The integrated graphics card offers 20 Execution Units (EUs), which represents the GT2 version of the Haswell GPU. Technically, the GPU seems similar to the Intel HD Graphics 4600 found on other Core i5 CPUs, but the clock rate of 400 - 1000 MHz is noticeably lower.

The i5-4400E is rated at a TDP of 37 W including the graphics card, memory controller and VRMs.

The Intel Core i5-4300U is an ULV (ultra low voltage) dual-core processor for ultrabooks launched in Fall 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 1.9 GHz, but can dynamically increase clock rates with Turbo Boost up to 2.9 GHz for 1 active core or 2.6 GHz for 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 performance per clock by almost 10 percent. Furthermore, new features like AVX2 and FMA should increase the performance in future applications.

The performance of the Core i5-4300U is similar to the old and slightly higher clocked Core i7-3517U. 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 HD Graphics 4400 offers 20 Execution Units (EUs) clocked at 200 - 1100 MHz with Turbo Boost, making it somewhat faster than the former HD Graphics 4000 at similar clock speeds. However, the HD 4400 is somewhat slower than the HD 5000 found on a number of other Haswell ULV models.

The i5-4300U is rated at a TDP of 15 W including the graphics card, memory controller, VRMs and the integrated chipset. Therefore, the CPU is suited for small ultrabooks 11-inches or greater.