Super Extended Graphics Array (SXGA) is a standard monitor resolution of 1280 × 1024 pixels. This display resolution is the "next step" above the XGA resolution that IBM developed in 1990.
The 1280 × 1024 resolution is not the standard 4:3 aspect ratio, but 5:4 (1.25:1 instead of 1.333:1). A standard 4:3 monitor using this resolution will have rectangular rather than square pixels, meaning that unless the software compensates for this the picture will be distorted, causing circles to appear elliptical.
There is a less common 1280 × 960 resolution that preserves the common 4:3 aspect ratio. It is sometimes unofficially called SXGA− to avoid confusion with the "standard" SXGA. Elsewhere this 4:3 resolution was also called UVGA (Ultra VGA): Since both sides are doubled from VGA the term Quad VGA would be a systematic one, but it is hardly ever used because of its initialism QVGA is strongly associated with the alternate meaning Quarter VGA (320 × 240).
SXGA is the most common native resolution of 17 inches and 19 inch LCD monitors. An LCD monitor with SXGA native resolution will typically have a physical 5:4 aspect ratio, preserving a 1:1 pixel aspect ratio.
SXGA is also a popular resolution for cell phone cameras, such as the Motorola Razr and most Samsung and LG phones. Although being taken over by newer UXGA (2.0-megapixel) cameras, the 1.3-megapixel was the most common around 2007.
Any CRT that can run 1280 × 1024 can also run 1280 × 960, which has the standard 4:3 ratio. A flat panel TFT screen, including one designed for 1280 × 1024, will show stretching distortion when set to display any resolution other than its native one, as the image needs to be interpolated to fit in the fixed grid display. Some TFT displays do not allow a user to disable this and will prevent the upper and lower portions of the screen from being used forcing a "letterbox" format when setting to a 4:3 ratio.
The 1280 × 1024 resolution became popular because at 24 bit/px color depth it fit well into 4 megabytes of video RAM. At the time, memory was extremely expensive. Using 1280 × 1024 at 24-bit color depth allowed using 3.75 MB of video RAM, fitting nicely with VRAM chip sizes which were available at the time (4 MB):
(1280 × 1024) px × 24 bit/px ÷ 8 bit/byte ÷ 220 byte/MB = 3.75 MB