HP Vectra VL5 5 Technical Reference Manual page 35

Transfer Rates Versus
Modes of Operation
Disk Capacity Versus
Modes of Addressing
to a channel, it should be in the master position (the connector that is
closest to the system board, unless the markings on the cables state
otherwise).
It is possible to mix a fast and a slow device, such as a hard disk drive and a
a CD-ROM, on the same channel without affecting the performance of the
fast device. The BIOS sends a command to each drive to determine,
automatically, the fastest configuration that it supports. However, in general,
the primary channel cable is recommended for hard disk drives, and the
secondary channel cable for CD-ROM drives.
The controller supports 32-bit Windows I/O transfers. Five PIO modes, and
three DMA modes are supported. The five supported PIO modes allow the
following transfer rates.
Mode
Cycle time (ns)
Transfer rate (MB/s)
The three DMA modes allow the following transfer rates:
Mode
Cycle time (ns)
Transfer rate (MB/s)
The amount of addressable space on a hard disk is limited by three factors:
the physical size of the hard disk, the addressing limit of the IDE hardware,
and the addressing limit of the BIOS. The Extended-CHS addressing scheme
allows larger disk capacities to be addressed than under CHS, by performing
a translation. If the Setup field has been set to
addressing (LBA) mode will be selected for each device that supports it.
Cylinders per
Device
CHS 64
ECHS 64
LBA -
0 1
600 383
3.33 5.22
0 1
480 150
4.2 13.3
Heads per
Sectors per Track
Cylinder
16 1024
256 1024
- 256 M (=2
2 System Board
Devices on the PCI Bus
2 3
240 180
8.33 11.1
2
120
16.7
, the logical block
automatic
Bytes per
Sector
512
512
28
) 512
4
120
16.7
Bytes per
Device
528 M
8.4 G
137 G
35