Editing Framebuffer (section)

== Graphics accelerators ==
{{See also|Video card|Graphics processing unit}}

As the demand for better graphics increased, hardware manufacturers created a way to decrease the amount of [[CPU]] time required to fill the framebuffer. This is commonly called ''graphics acceleration''. Common graphics drawing commands (many of them geometric) are sent to the graphics accelerator in their raw form. The accelerator then [[Rasterisation|rasterizes]] the results of the command to the framebuffer. This method frees the CPU to do other work.

Early accelerators focused on improving the performance of 2D [[GUI]] systems. While retaining these 2D capabilities, most modern accelerators focus on producing 3D imagery in real time. A common design uses a [[graphics library]] such as [[OpenGL]] or [[Direct3D]] which interfaces with the graphics driver to translate received commands to instructions for the accelerator's [[graphics processing unit]] (GPU). The GPU uses those instructions to compute the rasterized results and the results are [[bit blit]]ted to the framebuffer. The framebuffer's signal is then produced in combination with built-in video overlay devices (usually used to produce the mouse cursor without modifying the framebuffer's data) and any final special effects that are produced by modifying the output signal. An example of such final special effects was the [[spatial anti-aliasing]] technique used by the [[3dfx Voodoo]] cards. These cards add a slight blur to the output signal that makes aliasing of the rasterized graphics much less obvious.

At one time there were many manufacturers of graphics accelerators, including: [[3dfx Interactive]]; [[ATI Technologies|ATI]];  [[Hercules Computer Technology|Hercules]]; [[Trident Microsystems|Trident]];  [[Nvidia]]; [[Radius (hardware company)|Radius]]; [[S3 Graphics]]; [[Silicon Integrated Systems|SiS]] and [[Silicon Graphics]].  {{as of|2015}} the market for graphics accelerators for x86-based systems is dominated by Nvidia (acquired 3dfx in 2002), [[AMD]] (who acquired ATI in 2006), and [[Intel]].