The Intel HD Graphics (Bay Trail) is a low-end integrated Bay Trail graphics card found in certain Atom models (Z3770), nettops (J2850) and notebook SoCs (N3510). It supports DirectX 11 and is based on the Ivy Bridge GPU. Clock rates and shader cores, however, are considerably lower.
Compared to Ivy Bridge, which offers either 6 or 16 Execution Units, the HD Graphics (Bay Trail) comes with only 4 EUs. The core clock is significantly lower as well. Depending on the specific model, the maximum Turbo Boost is 896 MHz or less and the memory controller can support DDR3(L), DDR3L-RS or LPDDR3 in single- or dual-channel operation.
The fastest notebook models equipped with this GPU nearly match the performance of the HD Graphics (Sandy Bridge) and the AMD Radeon HD 6310. Therefore, older and less demanding Windows games like World of Warcraft or Half-Life 2 can be played fluently in very low settings. Performance is not sufficient for most modern titles.
Compared to competing ARM SoCs, Bay Trail outperforms the Adreno 320 (which can be found in different Qualcomm SoCs like the Snapdragon 600) and offers a performance similar to the Tegra 4 GPU. That is enough power to run even the most demanding Android games smoothly in very high resolutions as of 2013.
The integrated video decoder supports all popular codecs such as MPEG2, H.264, VC1, VP8 and MVC and is suitable for resolutions up to 4K up to 100 Mbit/s. The user can connect up to two displays via HDMI 1.4 (max. 1920 x 1080) or DisplayPort 1.2 (max. 2560 x 1600). Another new feature is the support for Wireless Display and Quick Sync, Intel's fast and power efficient H-264 hardware encoder. Some of these features are not available on all models.
Depending on the model, the power consumption of the entire SoC is somewhere between 2 and 10 W. The most efficient versions are therefore suitable for passively cooled tablets, whereas faster variants are used in larger subnotebooks with active cooling.
The Intel HD Graphics 4400 (GT2) is a processor graphics card included in some of the ULV Haswell processors of 2013. The relatively low base clock can be automatically overclocked using Turbo Boost technology. Depending on the processor model, the turbo clock rates may differ, resulting in varying graphics performance between models.
In comparison to the HD 4000, the HD 4400 graphics core has been modified extensively. The GPU now supports DirectX 11.1, OpenCL 1.2 and OpenGL 4.0. It also features an improved decoder for 4K videos and the fast Quick Sync encoder. Compared to the faster 4600, the 4400 offers the same amount of shaders, but lower clock speeds (see table of clock speeds of the different CPU models below).
The performance of the HD Graphics 4400 is somewhat below the HD 4600, since the GPU is designed for ULV models. Therefore, the clock rates are relatively low. Furthermore, the reduced TDP limits the Turbo Boost. Compared to the ULV versions of the Ivy Bridge HD 4000, the HD 4400 is about 20 - 30 percent faster. This performance boost is achieved by architectural improvements and an increased number of execution units: The GT2 version integrates 20 EUs, compared to 16 EUs for the old HD 4000. Depending on the clock rate, the HD 4400 matches the performance of a dedicated Radeon HD 7550M.
Due to the 22nm 3D Tri-Gate production process, the power consumption is relatively low. The HD Graphics 4400 can be found on ULV dual-core Haswell models with a TDP of 15 watts.
The Intel HD Graphics (Braswell) is an integrated graphics card in the low end SoCs of the Braswell series (e.g. Pentium N3700). It is based on the same architecture as the integrated GPU of the Broadwell graphics cards (e.g. HD Graphics 5300), but offers less shader cores and slower clock speeds.
The performance depends on the processor. The fastest models offer 16 EUs (shader cores) at 400 - 700 MHz. It should be about twice as fast as the old HD Graphics in Bay Trail SoCs. At the time of announcement in Q1 2015 the following models exist:
In the first CPUs the graphics card was only called Intel HD Graphics. Later (e.g. in the Celeron N3060) Intel renamed it to Intel HD Graphics 400 (Celeron with 12 EUs) and Intel HD Graphics 405 (Pentium with 16 EUs).
Gaming performance ist still only suited for older or less demanding games. Often also the processor is limited gaming performance (e.g. in the dual-core N3000).
The SoC also integrates a video decoding engine that should be able to handle 4K H.265 videos.