Asus CROSSHAIR IV EXTREME, User Manual, Page: 94 / 172

3-18 Chapter 3: BIOS setup
Block (Multi-Sector Transfer) M [Auto]
Enables or disables data multi-sectors transfers.
[Auto]
When set to [Auto], the data transfer from and to the device occurs
multiple sectors at a time if the device supports multi-sector
transfer feature.
[Disabled] When set to [Disabled], the data transfer from and to the device
occurs one sector at a time.
PIO Mode [Auto]
[Auto] Allows automatic selection of the PIO (Programmed input/output)
modes, which correspond to different data transfer rates.
[0] [1] – [4] Set the PIO mode to Mode 0, 1, 2, 3, or 4.
DMA Mode [Auto]
DMA (Direct Memory Access) allows your computer to transfer data to and from
the hardware devices installed with much less CPU overhead.
The DMA mode consists of SDMA (single-word DMA), MDMA (multi-word DMA),
and UDMA (Ultra DMA). Setting to [Auto] allows automatic selection of the DMA
mode, or you can select from the following options: [SWDMA1] [SWDMA2]
[MWDMA0] [MWDMA1] [MWDMA2] [UDMA0] [UDMA1] [UDMA2] [UDMA3]
[UDMA4] [UDMA5]
SMART Monitoring [Auto]
[Auto] Allows automatic selection of the S.M.A.R.T (Smart Monitoring,
Analysis, and Reporting Technology).
[Enabled] Enable the S.M.A.R.T feature.
[Disabled] Disable the S.M.A.R.T feature.
32Bit Data Transfer [Enabled]
[Enabled] Sets the IDE controller to combine two 16-bit reads from the hard
disk into a single 32-bit double word transfer to the processor. This
makes more efficient use of the PCI bus as fewer transactions are
needed for the transfer of a particular amount of data.
[Disabled] Disable this function.