The beta of Catalyst 12 revealed the truth.
"ATI Radeon X1050" = ati2mtag_RV370, PCIVEN_1002&DEV_5B63&SUBSYS_30001002<>br "ATI Radeon X1050 " =
ati2mtag_RV370, PCIVEN_1002&DEV_5B60&SUBSYS_30001002
"ATI Radeon X1050 Secondary" = ati2mtag_RV370, PCIVEN_1002&DEV_5B70&SUBSYS_30011002
"ATI Radeon X1050 Secondary " = ati2mtag_RV370, PCIVEN_1002&DEV_5B73&SUBSYS_30011002
RV370 has Shade model 2.0 supports just about to meet Vista demand and has four pipelines. It is build at 110 nanometre process has 75 million transistors, and full DX 9.0 support. You can read more about it here.
ATI is again playing pure renaming games as the bigger number is always better in customers' eyes, if not their brains. ยต