Fred Metcalf ([log in to unmask]) wrote: : I recall an utility I used on classic MPE/V systems to calculate optimum block : size, given that your record size is fixed as determined by the items. : The utility names eludes me now: maybe BLKSIZE? There used to be several programs to calculate optimal block sizes on MPE/V. With MPE/iX, there is no "unused space" between blocks and so the optimal block size is not the same. I believe that an overall block size that is a multiple of 4096 bytes is best for fixed length and U records, but for Variable length records most any large size is probably OK. -- James Overman HP Support Technology Lab Roseville, CA