An apparatus comprising: a host device comprising a host controller and a last level cache; a memory buffer, TMXB, device comprising: a receiver configured to receive a speculative read request from said host controller over an interface, wherein the speculative read request identifies a particular address in a memory, the speculative read request being determined to be sent in association with a lookup for data associated with the particular address of said last level cache of said host device based on a criterion determined by said host controller combining buffer resource availability and likelihood of a miss based on a memory line usage associated with the particular address; a scheduler configured to assign respective priorities to read requests to be handled by the TMXB device; and a memory controller configured to: obtain data from the particular address based on the speculative read request; store the data in a buffer; identify a demand read from the host controller corresponding to the speculative read request, wherein the demand read comprises a read request received after the speculative read request and identifies the particular address; and generate a read return comprising the data, wherein the read return is to be sent to the host controller over the interface in response to the demand read. a host device comprising a host controller and a last level cache; a memory buffer, TMXB, device comprising: a receiver configured to receive a speculative read request from said host controller over an interface, wherein the speculative read request identifies a particular address in a memory, the speculative read request being determined to be sent in association with a lookup for data associated with the particular address of said last level cache of said host device based on a criterion determined by said host controller combining buffer resource availability and likelihood of a miss based on a memory line usage associated with the particular address; a scheduler configured to assign respective priorities to read requests to be handled by the TMXB device; and a receiver configured to receive a speculative read request from said host controller over an interface, wherein the speculative read request identifies a particular address in a memory, the speculative read request being determined to be sent in association with a lookup for data associated with the particular address of said last level cache of said host device based on a criterion determined by said host controller combining buffer resource availability and likelihood of a miss based on a memory line usage associated with the particular address; a scheduler configured to assign respective priorities to read requests to be handled by the TMXB device; and a memory controller configured to: obtain data from the particular address based on the speculative read request; store the data in a buffer; identify a demand read from the host controller corresponding to the speculative read request, wherein the demand read comprises a read request received after the speculative read request and identifies the particular address; and generate a read return comprising the data, wherein the read return is to be sent to the host controller over the interface in response to the demand read. obtain data from the particular address based on the speculative read request; store the data in a buffer; identify a demand read from the host controller corresponding to the speculative read request, wherein the demand read comprises a read request received after the speculative read request and identifies the particular address; and generate a read return comprising the data, wherein the read return is to be sent to the host controller over the interface in response to the demand read.