Hi, deloptes wrote: > What does determine the DVD burning speed? Is it the DVD or the burner or > both?
The drive decides according to its assessment of the medium and the speed wish issued by the burn program. The drive announces a list of possible speeds, depending on the medium. E.g.: $ xorriso -outdev /dev/sr0 -list_speeds ... Media current: DVD+R/DL Media status : is blank Media summary: 0 sessions, 0 data blocks, 0 data, 8152m free Read speed : 11079k , 8.0xD Read speed : 4568k , 3.3xD Read speed L : 4568k , 3.3xD Read speed H : 11079k , 8.0xD Write speed : 5540k , 4.0xD Write speed : 3324k , 2.4xD Write speed L: 3324k , 2.4xD Write speed H: 5540k , 4.0xD So this drive offers write speed 4.0x and 2.4x, with 1x being 1385 KB/s. Other drives or media may offer more than just two write speeds. Media current: DVD-R sequential recording ... Write speed : 22160k , 16.0xD Write speed : 16620k , 12.0xD Write speed : 11080k , 8.0xD Write speed L: 11080k , 8.0xD Write speed H: 22160k , 16.0xD Those speeds are nominal. I.e. with several media types the drive will start slower and will slowly accelerate until it reaches the nominal speed at the outer rim of the medium. > How can I write DL dvd at 1x speed? The only certain influence from outside the drive is the data bandwith. If your program only sends 1385 KB/s to the drive, then it will not be able to surpass effective speed of 1x. But this might just mean that the drive waits a few hundred milliseconds until its buffer is sufficiently full, and then writes at its own chosen speed until its buffer is empty again. > I do not have option 1x - it gives me minimum 3x. Why is this so If it is Brasero, K3B, or Xfburn, then the offer stems from SCSI commands which inquire above speed list. (Either directly sent from the burn program or indirectly triggered by asking libburn which then asks the drive.) The offer "3x" is somewhat unusual for DVD+R DL. I only know this from DVD-RAM media. It might indeed stem from a 2.4x list entry. ---------------------------------------------------------------------- In general i think that the traditional advise to burn at 1x speed is an urban legend caused by drives at the brink of failure. Low speed makes low noise. So with with the fast spinning media BD-R, DVD-R, DVD+R, or CD-R it might be desirable to ask the drive for the lowest speed available. A speed wish of "1x" should tell it to try its best to be slow and silent. Have a nice day :) Thomas