In a PXI system with a controller PXI-8187, 1Gb ram and flash ram 512 Mb equipped with 2 DAQ cards pxi6289 I have to acquire 8 channels at 100KS/s for a long time (1000s). I am using 4 channels for each of the two boards and I have synchronized the two boards in the VI. To store in continuous way the data on the PXI HD I am using the example relative to the continuous acquisition with new DAQMx drivers and storing the data in binary like I32. Even If I perform a single while where simply I read the data in block of 1000 samples(per channels) and write on file I cannot manage this sampling frequency, I mean the backlog increase and after a time determined by the buffer size I go in buffer overrun. What is the maximum stream to disk rate??? What are the advices to realize on this PXI configuration (the best on the market) a datalogger with the requirements specified?? I have seen that you suggest to use the hsdl VI but these work only with the last release of NIDAQ and not with the M series DAQ, doesn`t it???? I have tried to select reading like I16 but I receive an error since the converter is at 18 bits. What do you suggest me??? Have you performed benchmark with M cards and this system??? Up to now the maximum performances that I can have without overrunning is 4 channels at 92KS/s or 47KS/s on 8 channels