3rd Gen Intel HD Graphics
The first generation of on-die Intel HD graphics, which was released with the Westmere architecture, wasn't actually on-die as such, rather on-package. The on-package graphics engine was separate from the CPU. Furthermore, it was built using the 45nm process and not the same 32nm process used by the actual CPU.
Then the second generation (Sandy Bridge) graphics changed all that by including the GPU on-die, meaning that it's also built using the same 32nm process as the CPU. Even though both are now under the same roof, the GPU is still independent of the CPU. It features its own clock domain, meaning that it can be clocked independently and can be powered down as needed.
This same design principle has been used for the Ivy Bridge architecture, Intel has simply added more horsepower. There are again two different versions of the Intel HD graphics and the Ivy Bridge processors can either use the HD 2500 or the faster HD 4000 graphics engine.
They can be clocked up as high as 1350MHz and support a maximum resolution of 2560x1600. Rendering support includes DirectX 11, OpenGL 3.1 and Shader Model Support 4.1. In contrast, the previous generation supported DirectX 10.1 and OpenGL 3.0.
The shaders, cores and execution units are what Intel calls EUs (Execution Units) with HD Graphics 2500 featuring six and the speedier HD Graphics 4000 getting sixteen. Interestingly, most Core i5 desktop processors use the slower HD Graphics 2500 engine, while all mobile processors receive the 4000 engine.
Besides the increased resolution support (up to 2560x1600 from 1920x1200 previously), the new Intel HD graphics now support triple monitors. The Sandy Bridge processors were limited to dual displays much like Nvidia graphics cards. However the new Ivy Bridge graphics can simultaneously support three displays which is a nice upgrade.
Intel claims the 3rd Generation Core processor graphics delivers greater 3D performance and API improvements over Sandy Bridge, such as 2x better performance in 3Dmark Vantage. Intel also says that the Ivy Bridge Intel HD 2500 is expected to perform ~10-20% higher than Sandy Bridge Intel HD 2000 on 3D graphics workloads. Right off the bat, we recommend you focus more on features and encoding performance than gaming, as you will see on our benchmarks later on this review.