Source:http://blogs.amd.com/play/2009/10/22/ati-catalyst%E2%84%A2-9-10-driver-%E2%80%93-what%E2%80%99s-new/
New Features: Official ATI Catalyst WHQL release supporting ATI Radeon HD 5800 series GPUs
ATI Catalyst 9.10 now includes full GPU support for the award winning ATI HD Radeon 5800...
Over on XS with ACC enabled Propus with L3
http://valid.canardpc.com/show_oc.php?id=661740
Same as the Denebs outlined in red
Here are some testing with L3 enabled
http://www.xtremesystems.org/forums/showpost.php?p=3981450&postcount=45