Possible values of an option:
[Auto], [Enabled], [Disabled]
[Auto], [Mode 0], [Mode 1], [Mode 2], [Mode 3], [Mode 4], [Mode 5], [Mode 6], [Disabled]
[Auto], [SWDMA 0], [SWDMA 1], [SWDMA 2], [MWDMA 0], [MWDMA 1], [MWDMA 2], [UDMA 0], [UDMA 1], [UDMA 2], [UDMA 3], [UDMA 4], [UDMA 5], [UDMA 6]
The option description:
The option allows to specify a direct memory access mode (DMA — Direct Memory Access, UDMA — Ultra DMA), used at operation of the drive connected to the given channel of the standard IDE/SATA-controler of a chipset. As a rule, it is possible to use a mode of automatic determination of possibilities of the drive ([Auto]). In case of problems with the given specific disk it is possible to try to disconnect mode DMA ([Disabled]). Only it is necessary to mean that it leads to essential falling of productivity of a disk subsystem, to use this measure it is possible only as a last resort.
Frequently among values of the given option are present not only the variants, giving the chance to include or disconnect a direct memory access mode, but also the values, allowing to specify a specific mode. Then, if the drive works unstable, it is possible to try to pass instead of blackout DMA to one of low modes. Probably, it completely solves a problem, thus not so fatally affected productivity of a disk subsystem.
For help we result titles of modes and the maximum speed of a data interchange with the drive of interface IDE or SATA for each of modes (it is necessary to consider that modes DMA add modes PIO Mode, providing essentially an operation great speed):
|Single-Word DMA 0||2.1 Mb/sek|
|Single-Word DMA 1||4.2 Mb/sek|
|Single-Word DMA 2||8.3 Mb/sek|
|Multi-Word DMA 0||4.2 Mb/sek|
|Multi-Word DMA 1||13.3 Mb/sek|
|Multi-Word DMA 2||16.7 Mb/sek|
|Ultra DMA 0||16.7 Mb/sek|
|Ultra DMA 1||25.0 Mb/sek|
|Ultra DMA 2 or Ultra DMA 33||33.3 Mb/sek|
|Ultra DMA 3||44.4 Mb/sek|
|Ultra DMA 4 or Ultra DMA 66||66.7 Mb/sek|
|Ultra DMA 5 or Ultra DMA 100||100.0 Mb/sek|
|Ultra DMA 6 or Ultra DMA 133||133.0 Mb/sek|
All modern hard disks with interface IDE are capable to work at least in mode Ultra DMA 100. Optical disk drives and to it similar devices normally use mode Ultra DMA 33, there are the models using Ultra DMA 66. Thus, for more or less modern hard disks should be installed combination PIO Mode 4 and Ultra DMA 100 (as the variant, Ultra DMA 133), but is better to install value [Auto]. For optical disk drives and to it of similar devices — PIO Mode 4 and Ultra DMA 33 (as a variant, Ultra DMA 66), but, besides, it is better to use [Auto].
Other options identical to destination: