Intel HD Graphics (Bay Trail) vs Intel HD Graphics 2500 vs Intel HD Graphics 5500

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 2500

The Intel HD Graphics 2500 (or Ivy Bridge GT1) is an integrated graphics card in the Ivy Bridge codenamed desktop processors. It is the successor the the Intel HD Graphics 2000 in the Sandy Bridge CPUs and performs between the old HD 2000 and 3000 GPU (see benchmarks below). Usually it is used in the cheaper desktop Ivy bridge CPUs. The mobile version is simply called Intel HD Graphics and integrated in the Pentium and Celeron line.

Compared to the faster HD Graphics 4000, the 2500 one features less Execution Units (6 versus 16) and only one texture sampler. Therefore, the performance is clearly worse and only suited for low demanding gaming. Intel states a 10 to 15% higher performance compared to the old Sandy Bridge based HD Graphics 2000. Therefore, only older casual games with low requirements are playable with the HD 2500.

A speciality of the Ivy Bridge GPUs is that 4x MSAA is supported in hardware now. However, 2x is only supported through software.  The algorithm to support 2x is going through the 4x pipeline with a software algorithm, so performance is similar to 4x MSAA.

The integrated video decoder called Multi Format Codec Engine (MFX) was also improved and should allow even simultaneus 4K video decoding. DXVAChecker lists MPEG2, VC1, WMV9, and H264 as supported codecs. QuickSync for fast transcoding of videos was also optimized for higher performance and better image quality.

Another new feature is the support for up to 3 independent displays as AMD offers with theirs Eyefinity support (up to 6 displays).

Due to the 22nm 3D Tri-Gate production process, the power consumption is relatively low (the development was focused on performance per Watt). 

Intel HD Graphics 5500

The Intel HD Graphics 5500 (GT2) 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 i5-5200U or i7-5600U. While Core i5 and Core i7 chips feature 24 EUs, the Core i3 version offers just 23 EUs. Depending on the specific CPU, the maximum GPU frequency varies between 850 and 950 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 5500 represents the mid-range version of the Broadwell GPU family and consists of one slice with 24 EUs. Beyond that, there is also a low-end variant (GT1, 12 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

Depending on the specific CPU, the maximum GPU frequency varies between 850 and 950 MHz. Due to the low TDP, however, the average clock in 3D applications will be somewhat lower.

Equipped with fast dual-channel memory, the HD Graphics 5500 outperforms the HD Graphics 4400 (Haswell, 20 EUs) by 20 - 25 percent and also beats the HD Graphics 5000 (Haswell, 40 EUs). However, even a low-end dedicated GeForce 820M ist about 10 - 30 percent faster than the HD 5500. 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 (7.5 or 10 W), which has a significant impact on performance.