OpenAtom has shown good scaling up to 20,480 processors of IBM's Blue Gene/L and 4,096 processors of Cray XT3.
Robert Cray | Cray | Seymour Cray | Cray X-MP | North Cray | Cray Wanderers F.C. | Cray-1 | St. Paul's Cray | St Paul's Cray | Foots Cray Place | Cray Y-MP | Cray XT3 | Cray Time Sharing System | Cray CS6400 |