DDR4 Memory Sample Clauses

DDR4 Memory. To test the DDR4 memory a simple OpenCL kernel was created. The time taken to read and write data to the global memory, equivalent to the DDR4 memory attached to the ARM, was measured. The peak OpenCL Shared DDR4 Bandwidth was measured at 4.5 GBytes/Sec (Writes), dropping to ~4.1 GBtytes/Sec when arm is also streaming to DDR memory. This was to be expected given the limitations imposed on the L3 interconnect clock frequency and the choice of default QoS settings. Table 11 illustrates the effects on ARM bandwidth when an OpenCL kernel is streaming data to the DDR memory. The ARM peak bandwidth is ~0.78 GBytes/Sec when an OpenCL kernel is busy accessing the memory. Function Best Rate MB/s Avg time Min time Max time Copy 764.0 0.352019 0.209427 0.370985 Scale 289.4 0.554557 0.552804 0.557343 Add 336.6 0.714664 0.712951 0.719603 Triad 325.6 0.771651 0.737148 0.779742 Table 11 : ARM memory bandwidth running the “Stream” benchmark when throttled by OpenCL kernel