Intel HD Graphics (Broadwell) vs Intel HD Graphics (Bay Trail)

Intel HD Graphics (Broadwell)

The Intel HD Graphics (Broadwell) (GT1) is an integrated Broadwell graphics card revealed in Q1 2015. It can be found in several low-end CPUs such as the Pentium 3805U or Celeron 3755U. The so-called GT1 GPU offers 12 EUs (Execution Units) and therefore somewhat more shader power than the previous HD Graphics (Haswell). The clock range may depend on the specific model it is built into.

Architecture and Features

Broadwell features a GPU based on the Intel Gen8 architecture, which has been optimized in various aspects compared to the previous Gen7.5 (Haswell). In case of the GT1 version, the shader arrays called "subslice" have been reorganized and now offer 6 Execution Units (EUs) each. Two subslices form a "slice" for a total of 12 EUs. Combined with other improvements such as larger L1 caches and an optimized frontend, the integrated GPU has become faster and more efficient than its predecessor.

The HD Graphics (Broadwell) represents the low-end version of the Broadwell GPU family and consists of one slice with 12 EUs. Beyond that, there is also a mid-range variant (GT2, 24 EUs) as well as higher-end models (GT3/GT3e + eDRAM, 48 EUs).

All Broadwell GPUs support OpenCL 2.0 and DirectX 12 (FL 11_1). The video engine can now decode H.265 using both fixed function hardware as well as available GPU shaders. Up to three displays can be connected via DP 1.2/eDP 1.3 (max. 3840 x 2160 @ 60 Hz) or HDMI 1.4a (max. 3840 x 2160 @ 24 Hz). HDMI 2.0, however, is not supported.

Performance

Even though the HD Graphics (Broadwell) is clocked a bit lower, the performance should be clearly above the HD Graphics (Haswell) and similar to the HD Graphics 4000. Nevertheless, only a few games as of 2014/2015 will run fluently at (very) low settings, e.g. Dota 2 or Sims 4.

Power Consumption

Utilizing a new 14 nm process, the HD Graphics (Broadwell) can be found in ULV models (15 W) as well as regular dual core CPUs (37 W, not yet presented). The TDP is flexible and can be further reduced, which has a significant impact on performance.

Intel HD Graphics (Bay Trail)

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.