Intel Haswell to Feature Two New DirectX Extensions
Intel has announced that its upcoming Haswell series of processors will feature two new DirectX extensions, PixelSync and InstantAccess. The former, PixelSync, enables Order Independent Transparency (OIT), which speeds up the sorting of transparent graphical elements, for example windows, by ensuring they are rendered in the correct order. OIT is a common feature found in DirectX 11 games, however it is not a feature of the API.
Current methods of OIT involve using large amounts of VRAM and bandwidth, neither of which most integrated graphics solutions, including Haswell, excel at. For this reason, Intel has developed its own implementation of the technology which relies less on the bandwidth and VRAM of the processor.
The other extension, InstantAccess, enables the CPU part of the processor to access a location in the GPU memory (even though the CPU and GPU parts of the chip share the same memory, they each have their own allocated sections). This alleviates the requirement to 'copy' the data to the CPU memory, which is very costly in terms of performance.