ahead for additional sectors this limit can be set to accept any request falling within a specified range of sectors to pass the sequential test if the request does not meet the sequential test of step 530 the algorithm proceeds to step 550 where the designated disk is changed and the counter is reset to zero otherwise an additional step is performed in step 540 step 540 checks to see if the counter is equal to the threshold as before if the answer is yes step 550 is performed to toggle the designated disk and to reset the counter to zero otherwise step 550 is skipped step 560 sends the read request to the designated disk and increments the counter by 1 step 570 determines from the average size of data blocks requested in the most recent reads if the threshold value needs to be changed this derives from the fact that during testing of this algorithm it was realized that when small blocks of data were being read e g 0 5k the threshold value needed to be larger than if relatively large blocks of information e g 32k were being read it is anticipated that the threshold value would not be changed rapidly but if a general shift in the size of the blocks read does occur this provides a means of further optimizing performance if it is determined that a change in the threshold value would be beneficial the process goes to step 580 where the threshold value is set to a more efficient value otherwise this step is skipped finally in step 590 it is determined if further requests are being received if they are the algorithm continues from step 520 otherwise the process is complete using this enhanced algorithm adds some complexity and requires the.