Not terribly common, not terribly useful. These cards do not work in Linux, and this is not likely to change unless Sun releases detailed hardware specifications, or a driver.
Under Solaris, it is theoretically possible to run Linux, or old versions of Windows.
This is the grandfather of the SunPCI boards.
|SunPC Accelerator SX||501-1980||i486 16 MHz|
|SunPC Accelerator DX||501-1981||i486 25 MHz|
|SunPC Accelerator DX2||501-2874||i486 66 MHz|
|SunPC||501-4230||i586 133 MHz|