IMPACT (computer graphics)

{{Short description|Graphics subsystem by Silicon Graphics}}

{{Infobox GPU

| name = IMPACT

| designfirm = Silicon Graphics

| image =

|caption =

| codename =

| created = {{start date and age|1995}}

| entry =

| midrange = Solid IMPACT, SI, SE

| highend = High IMPACT, SSI, SSE

| enthusiast = Maximum IMPACT, MXI, MXE

|predecessor = Extreme Graphics

|successor = SGI VPro

| support status = Unsupported

|architecture= }}

IMPACT (sometimes spelled Impact) is a computer graphics architecture for Silicon Graphics computer workstations. IMPACT Graphics was developed in 1995 and was available as a high-end graphics option on workstations released during the mid-1990s. IMPACT graphics gives the workstation real-time 2D and 3D graphics rendering capability similar to that of even high-end PCs made well after IMPACT's introduction. IMPACT graphics systems consist of either one or two Geometry Engines and one or two Raster Engines in various configurations.{{cite web|url=http://www.futuretech.blinkenlights.nl/i2info.html#3.3|title=Later (Newer) Indigo2 Technologies|accessdate=2016-04-13|archive-date=2016-03-24|archive-url=https://web.archive.org/web/20160324041427/http://www.futuretech.blinkenlights.nl/i2info.html#3.3|url-status=dead}}

IMPACT graphics consists of five graphics subsystems: the Command Engine, Geometry Subsystem, Raster Engine, framebuffer and Display Subsystem. IMPACT Graphics can produce resolutions up to 1600 x 1200 pixels with 32-bit color{{cite web|url=http://sgistuff.g-lenerz.de/graphics/impact.html|title=Impact graphics options by Gerhard Lenerz|archivedate=2005-01-28|archiveurl=https://web.archive.org/web/20050128090515/http://sgistuff.g-lenerz.de/graphics/impact.html|accessdate=2016-04-13}} and can also process unencoded NTSC and PAL analog television signals.

IMPACT graphics subsystems come in three configurations for SGI Indigo2 IMPACT workstations: Solid IMPACT, High IMPACT, and Maximum IMPACT. The equivalent configurations also exist for the SGI Octane workstation but are referred to as SI, SSI, and MXI (I-series). Later Octane workstations used a similar configuration but with updated ASIC chips and are referred to as SE, SSE, and MXE (E-series). IMPACT uses Rambus RDRAM for texture memory.{{cite web|url=http://www.futuretech.blinkenlights.nl/octnarch.html|title=Octane Architecture|accessdate=2016-04-13}}

The IMPACT graphics architecture was superseded by SGI's VPro graphics architecture in 1997.