What is dummy read cdb for CD/DVD?


Someone told me that seek and dummy read cdb can help improve the read speed. I do not know what is dummy read cdb. Would you like to give some introduction on this point ?



IMO, “someone” told you something that is not true.

Yep, chef is right, and I’ve checked through MMC draft docs (optical drive comands) there is no dummy read cdb.

Hmm, the seek command shouldn’t improve the read speed anyway. The read command doesn’t affect the read speed directly - it is controlled by the drive’s set speed fixed to CAV / CLV / PCAV etc and it monitoring the number of errors. If a disc has many C1 / C2 errors then it slows down - whether you use seek or not.

Thanks a lot for your help. Then I have another question: how can I check if the drive’s set speed is fixed to CAV or CLV ? Thanks.

Good question, unfortunately MMC doesn’t define a command to give that information. The only way I know of is to measure the rate during the imaging of the disc. The tool Nero Disc Speed does quite well at this.