The original raspberry pi documentation did kind of give people the wrong idea. The whole block with the VPUs, ISPs, mpeg4 codec and 3d pipeline could be descr

The original raspberry pi documentation did kind of give people the wrong idea. The whole block with the VPUs, ISPs, mpeg4 codec and 3d pipeline could be described as a "GPU", and the gpu firmware is the firmware that runs it. Modern Desktop CPUs also contain a management/security cpu core which runs everything. And that correctly described as GPU firmware, though its commonly called vBIOS. But the VPUs are so much more than a management processor for the 3d pipeline. They have a huge vector array and can do software encoded/decoding of video up to 480p MPEG2 (videocore 4 added hardware h264 codecs that could do 1080p) I like to think of the VPUs as multimedia co-processor cores. The ipod video used the VideoCore 2 as it's gpu. It had an arm SoC as it's main cpu and a separate videocore chip. The videocore handled all display output and video decoding. It has no 3d pipeline, but they wrote an software opengl implementation which runs on the VPU to implement the games. There are actually a few set-top boxes (and maybe a cellphone) which just just the videocore VPUs the main cpu. It's flexible enough for that.