Supermicro H8DGU User Manual page 57

Chapter 4: BIOS
Primary/Secondary/Third/Fourth IDE Master/Slave
LBA/Large Mode
LBA (Logical Block Addressing) is a method of addressing data on a disk
drive. The options are Disabled and Auto.
Block (Multi-Sector Transfer)
Block mode boosts IDE drive performance by increasing the amount of data
transferred. Only 512 bytes of data can be transferred per interrupt if block
mode is not used. Block mode allows transfers of up to 64 KB per interrupt.
Select "Disabled" to allow the data to be transferred from and to the device
one sector at a time. Select "Auto" to allows the data transfer from and to the
device occur multiple sectors at a time if the device supports it. The options
are Auto and Disabled.
PIO Mode
PIO (Programmable I/O) mode programs timing cycles between the IDE drive
and the programmable IDE controller. As the PIO mode increases, the cycle
time decreases.
The options are Auto, 0, 1, 2, 3, and 4. Select Auto to allow BIOS to auto
detect the PIO mode. Use this value if the IDE disk drive support cannot be
determined. Select 0 to allow BIOS to use PIO mode 0, which has a data
transfer rate of 3.3 MBs. Select 1 to allow BIOS to use PIO mode 1, which
has a data transfer rate of 5.2 MBs. Select 2 to allow BIOS to use PIO mode
2, which has a data transfer rate of 8.3 MBs. Select 3 to allow BIOS to use
PIO mode 3, which has a data transfer rate of 11.1 MBs. Select 4 to allow
BIOS to use PIO mode 4, which has a data transfer rate of 16.6 MBs. This
setting generally works with all hard disk drives manufactured after 1999.
For other disk drives, such as IDE CD-ROM drives, check the specifi cations
of the drive.
DMA Mode
Selects the DMA Mode. Options are Auto, SWDMA0, SWDMA1, SWDMA2,
MWDMA0. MDWDMA1, MWDMA2, UDMA0. UDMA1, UDMA2, UDMA3,
UDMA4 and UDMA5. (SWDMA=Single Word DMA, MWDMA=Multi Word
DMA, UDMA=UltraDMA.)
4-7