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 mode of direct access to memory (DMA — Direct Memory Access, UDMA — Ultra DMA), used at work of the store connected to the given channel of the standard IDE/SATA-controller of a chipset. As a rule, it is possible to use a mode of automatic definition of possibilities of the store ([Auto]). In case of problems with the given concrete disk it is possible to try to disconnect mode DMA ([Disabled]). Only it is necessary to mean that it will lead 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 mode of direct access to memory, but also the values, allowing to specify a concrete mode. Then, if the store works astably, it is possible to try to pass instead of blackout DMA to one of younger modes. Probably, it completely will solve a problem, thus not so fatally having affected productivity of a disk subsystem.
For the inquiry we will result names of modes and the maximum speed of data exchange with the store of interface IDE or SATA for each of modes (it is necessary to consider that modes DMA supplement modes PIO Mode, providing essentially a work 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. Drives of optical disks and to it similar devices usually use mode Ultra DMA 33, there are the models using Ultra DMA 66. Thus, for more or less modern hard disks should be established combination PIO Mode 4 and Ultra DMA 100 (as the variant, Ultra DMA 133), but is better to establish value [Auto]. For drives of optical disks 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: