How well does NI-DAQmx perform high-speed streaming to disk?
NI-DAQmx primarily affects streaming-to-disk performance because it uses CPU bandwidth while moving and scaling data acquired by devices. Therefore, on systems where CPU bandwidth is a limiting factor, it is critical that NI-DAQmx efficiently uses the CPU. NI-DAQmx has undergone multiple optimizations since its first release to reduce CPU usage while reading and writing. For example, between the NI-DAQ 7.3 and 7.4 releases, the performance of scaled analog input benchmarks has increased from 8 to 60 percent. The performance of unscaled analog input benchmarks has increased from 12 to 40 percent. The performance increase translates directly to higher streaming-to-disk throughput on systems where CPU bandwidth is an issue. NI-DAQmx implements an extremely simple form of compression. Bits at the end of samples are simply thrown out and the resulting samples are packed into memory. NI-DAQmx does not implement any other lossless or lossy compression algorithms such as LZW or JPEG. In some c
