In one embodiment, a rate adaptation device comprises one or more input/output (I/O) ports coupled to a first network operating at a first data transmission rate, a first physical coding sublayer (PCS) receiver to receive a stream of PCS blocks from the first network, an idle symbol remover to remove a sequence of idle symbols from the first PCS block and combine the one or more non-idle PCS symbols in a buffer with one or more non-idle PCS symbols from a second PCS block to form a third PCS block, and a PCS transmitter to transmit the third PCS block to a second network operating at a second data transmission rate.