Intel HD Graphics (Bay Trail) vs Intel HD Graphics (Braswell) vs Intel HD Graphics 6000

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.

Intel HD Graphics (Braswell)

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:

• Pentium N3700: 16 EUs @ 400 - 700 MHz, Dual-Channel Memory
• Celeron N3150: 12 EUs @ 320 - 640 MHz, Dual-Channel Memory
• Celeron N3050: 12 EUs @ 320 - 600 MHz, Dual-Channel Memory
• Celeron N3000: 12 EUs @ 320 - 600 MHz, Dual-Channel Memory

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.

Intel HD Graphics 6000

The Intel HD Graphics 6000 (GT3) is an integrated Broadwell graphics card revealed in Q1 2015. It can be found in several ULV SoCs (15 W TDP) such as the Core i5-5250U or i7-5650U. The so-called GT3 GPU offers 48 EUs (Execution Units) and therefore somewhat more shader power than the previous HD 5000 (40 EUs). Depending on the specific CPU, the maximum GPU frequency varies between 950 and 1000 MHz.

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). Inter alia, the shader arrays called "subslice" have been reorganized and now offer 8 Execution Units (EUs) each. Three subslices form a "slice" for a total of 24 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 6000 represents the top-end version of the Broadwell GPU family and consists of two slices with 48 EUs. Beyond that, there is also a low-end (GT1, 12 EUs), a mid-range (GT2, 24 EUs) and a high-end variant (GT3e, 48 EUs + eDRAM).

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

Depending on the specific CPU, the maximum GPU frequency varies between 950 and 1000 MHz. Due to the low TDP, however, the average clock in 3D applications will be significantly lower. Overall, the HD Graphics 6000 outperforms the previous HD 5000 by 20 - 25 percent and offers a performance slightly below a dedicated GeForce 820M.

Games as of 2014/2015 will usually run fluently only at (very) low settings.

Power Consumption

Utilizing a new 14 nm process, the Broadwell ULV chips are specified at just 15 W TDP and therefore suited for thin ultrabooks. The TDP is flexible and can be further reduced (9.5 W), which has a significant impact on performance.