Radiation hardened Power PC (#RAD750) used on #Opportunity rover.

200K for each board, twins and they run identical VxWorks real-time operating systems.
On land in 06/08/2012 it used the “Side-A” computer, after ~ a year (200 Sol of 669 Sol planned) #NASA swap to side-B for memory corruption on side-A (256 MB of DRAM on each board)

Actually the #rover is at 2320 martian sols (or 2383 earth days, 1696 days longer than expected)

(Each boardr also has 256 kB of EEPROM and 2GB of flash memory)