"The Flex AMF benchmark makes a RemoteObject request to the server for 5000 rows. The server serializes the data in the AMF format. AMF is a binary object format for ActionScript objects in the Flash Virtual Machine. The client gets the AMF data over HTTP, shoves it into memory, then updates the DataGrid with the 5000 rows. The DataGrid supports client side sorting.
Out of all the benchmarks AMF is by far the fastest and smallest across the wire. There is nearly no parse time because the objects are already AS objects (instead of XML or another text based object representation). Render time is also extremely fast due to Flash's, Mozilla Tamarin JIT'd VM. If you try sorting you will again see the performance of the VM. Notice that sorting is faster in the AMF benchmark than in the E4X benchmark because the objects are typed AS objects rather than XML objects."