Here us my 5 cents, ATI/AMD usualy gives some range of devids to all cards based on same chip, for example rv770 - 9440 9441 9442 9443 (4870 4870x2 4850 4850x2 cards).

so, lets look

"ATI Radeon HD 5800 Series" = ati2mtag_Evergreen, PCI\VEN_1002&DEV_6898
"ATI Radeon HD 5800 Series " = ati2mtag_Evergreen, PCI\VEN_1002&DEV_6899
"ATI Radeon HD 5900 Series" = ati2mtag_Evergreen, PCI\VEN_1002&DEV_689C
"ATI Radeon HD 5900 Series " = ati2mtag_Evergreen, PCI\VEN_1002&DEV_689D

same devid range for all 4 cards - 6890-689F, so all four is rv870 based cards.

5900 is hemlock, and no need for any 3dparty confirmations