Preferred embodiments of the present invention increase the efficiency of access to a constructed list of memory locations, or DMA list by a host processor. In order to circumvent the problem of latency between an I/O device and the host processor, preferred embodiments of the present invention store a copy of the DMA head pointer in the system memory, as well as on the I/O device. When the head pointer data is changed on the I/O device, the I/O device will use DMA to write the updated head pointer back to system memory.