Refinement of the 68020 CPU from Motorola. The principle difference being that the 68030 possessed separate data and instruction caches of 256 bytes each, whereas the 68020 only had a single 256 byte instruction cache. Also the 68030 generally had a built-in MMU (although the 68EC030 did not), whereas the 68020 needed an external one. Neither had a built-in FPU.
The Amiga 3000 shipped with a 16Mhz or 25MHz 68030, while some Amiga 4000s sported a 25MHz 68EC030.