Graphics address remapping table

<p>The graphics address remapping table (GART), also known as the graphics aperture remapping table, or graphics translation table (GTT), is an <a href="/facts/IOMMU/lvVkzUyw">I/O memory management unit</a> (IOMMU) used by <a href="/facts/Accelerated_Graphics_Port/kmrNmn8U">Accelerated Graphics Port</a> (AGP) and <a href="/facts/PCI_Express/ADhsLCUK">PCI Express</a> (PCIe) <a href="/facts/Graphics_card/bcKfPyFt">graphics cards</a>. The GART allows the graphics card <a href="/facts/Direct_memory_access/DWuVgclV">direct memory access</a> (DMA) to the host system memory, through which buffers of <a href="/facts/Texture_mapping/9gDTsuXN">textures</a>, <a href="/facts/Polygon_mesh/6WLD80ER">polygon meshes</a> and other data are loaded. <a href="/facts/AMD/CB1G7QTb">AMD</a> later reused the same mechanism for <a href="/facts/I%2fO_virtualization/y0aaot2D">I/O virtualization</a> with other peripherals including <a href="/facts/Disk_controller/dfRSYlMq">disk controllers</a> and <a href="/facts/Network_adapter/wyf5FR29">network adapters</a>.
</p><p>A GART is used as a means of data exchange between the <a href="/facts/Primary_storage/wPHKFpdx">main memory</a> and <a href="/facts/Video_memory/koI9FGo5">video memory</a> through which buffers (i.e. paging/swapping) of <a href="/facts/Texture_mapping/9gDTsuXN">textures</a>, <a href="/facts/Polygon_mesh/6WLD80ER">polygon meshes</a> and other data are loaded, but can also be used to expand the amount of video memory available for systems with only integrated or shared graphics (i.e. no discrete or inbuilt graphics processor), such as <a href="/facts/Intel_HD_Graphics/p87h2lSE">Intel HD Graphics</a> processors.  However, this type of memory (expansion) remapping has a caveat that affects the entire system: specifically, any GART, pre-allocated memory becomes pooled and cannot be utilised for any other purposes but graphics memory and display rendering. 
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Graphics address remapping table open-in-new

Graphics address remapping table