This is from the Feurio help:
[i]"Size of read block: K
The number of sectors that are transfered from the device at each read command can be set here.
Basically it would be useful to chose the biggest possible value, because both the performance will be increased and no jitter errors can occur when reading a block.
Though SCSI host adapters can only transfer a certain amount of data per command, Feurio!Â® will inquire the maximum amount of data from the SCSI host adapter and appropriate restrict the transfer rate.
Attention: Besides the limit by the host adapter (e. g. 4 GB by AdaptecÂ® adapters) WindowsÂ® limits the maximum transfer size as well!
If the drive is accessed via â€DeviceIoControlâ€ /i[i] a special function will return the maximum transfer size supported by WindowsÂ®, so Feurio!Â® will be able to address the device correctly.
However, if the drive is accessed via â€ASPIâ€, there is (according to the ASPI documentation and the possible status parameters) no limit. Severals tests have shown, that there still IS a limit. Partially the limit is the same as in â€DeviceIoControlâ€, partially itÂ´s higher.
Usually the limit was 69632 bytes (i. e. 29 sectors).
Exceeding this limit caused errors (entries in the system protocol) like e. g. â€The driver has detected a controller error in \Device\ScsiPort1â€.
Furthermore some SCSI controllers as well as most of the IDE controllers have problems if the transfer size exceeds 65535 bytes (i. e. 27 sectors).
The value should usually be (not higher than) 27 sectors!
From: Feurio! CD-Writer online help (c) by Fangmeier Systemprogrammierung"[/i]