2.4.3.2. DDR-Free Streaming Performance
DDR-free mode relies solely on on-chip memory for data storage. This mode is particularly beneficial for applications where minimizing latency and maximizing throughput are critical, as it eliminates the need for data transfer between on-chip and off-chip memory.
- Memory Constraints
The architecture file must have sufficient on-chip memory to accommodate all graph parameters in the filter scratchpad. There must also be sufficient on-chip memory to store all intermediate surfaces in the stream buffer.
- High Coupling to Graph
Loading a new graph into a DDR-free instance of the FPGA AI Suite IP requires briefly pausing inference operations while the new graph is loaded via the CSR interface. By contrast, the IP can switch between graphs without any additional delay when using external DDR memory.
For more information about DDR-free operation, refer to Using FPGA AI Suite in Hostless DDR-Free Mode.
For performance values, refer to ResNet18 (PyTorch) in Model Performance.