I dont know if Sun paid Cray to get their name on it, but I'm sure Cray did not pick it up because of the fantastic CPU performance.
The entire sun4d series had the same fundamental issue: When a CPU missed local cache and fetched across the "X-Bus", instead of returning a single word as fast as possible in a 2-cycle packet, the memory board did four sequential memory accesses and sent a 9-cycle packet.
The net effect of this was to turn it into an 8MHz machine, if your program did not fit well in the 1Mbyte CPU-cache.
On the plus side, you could stick amazing numbers of S-bus cards into those boxes, for instance if you needed a lot of disks for statistical seek-time reduction.
We had five SS1000's as file servers, they had 9 differential SCSI controllers each, with each controller servicing three Seagate 2GB "Elite" drives - a whopping total of 270 GB, mirrored and striped with Veritas.