1. An apparatus comprising: a memory controller hub adapted to be coupled to a processing device, the memory controller hub including: an input/output (I/O) module comprising a protocol stack adapted to receive a first number of transactions in a first order from the processing device, and a re-order module coupled to the I/O module, the re-order module adapted to: identify an opportunity to re-order the first number of transactions to a second order, which is different from the first order, identify, from one or more packets in the first number of transactions, that a relaxed ordering attribute field indicates that relaxed ordering can be applied to the first number of transactions, and re-order the first number of transactions to the second order, based at least in part on the relaxed ordering attribute field, wherein priority of a plurality of corresponding transactions of the first number of transactions is to be maintained in the second order and the corresponding transactions reference the same memory location.