Linn (the hifi people, not the drum machine people) made a CPU called "Rekursiv" (because they like odd spelling like that) which had objects and GC implemented in hardware, on a couple of very large custom chips on VMEBus boards. These were horrendously expensive and were to be plugged into a Sun 3 box, making it all quite breathtakingly spendy.

When Sun brought out their SPARC hardware the language they run was ported to that, and ran about four times faster clock-for-clock.

You can gain some measure of the Rekursiv's success from the fact that the only complete machine known to still exist can be found on the bottom of the Forth and Clyde Canal, somewhere around the Possil Road Aqueduct.