M
M
X
X
3
3
6
6
L
L
E
E
-
-
U
U
/
/
M
M
X
X
3
3
6
6
L
L
E
E
-
-
U
U
N
N
O
O
n
n
l
l
i
i
n
n
e
e
M
M
a
a
n
n
u
u
a
a
l
l
This motherboard supports Ultra
,
and
IDE devices. Following table lists the transfer rate of IDE PIO and
DMA modes. The IDE bus is 16-bit, which means every transfer is two bytes.
Mode
Clock Period
Clock Count Cycle Time
Data Transfer Rate
PIO mode 0
30ns
20
600ns
(1/600ns) x 2byte = 3.3MB/s
PIO mode 1
30ns
13
383ns
(1/383ns) x 2byte = 5.2MB/s
PIO mode 2
30ns
8
240ns
(1/240ns) x 2byte = 8.3MB/s
PIO mode 3
30ns
6
180ns
(1/180ns) x 2byte = 11.1MB/s
PIO mode 4
30ns
4
120ns
(1/120ns) x 2byte = 16.6MB/s
DMA mode 0
30ns
16
480ns
(1/480ns) x 2byte = 4.16MB/s
DMA mode 1
30ns
5
150ns
(1/150ns) x 2byte = 13.3MB/s
DMA mode 2
30ns
4
120ns
(1/120ns) x 2byte = 16.6MB/s
UDMA 33
30ns
4
120ns
(1/120ns) x 2byte x2 = 33MB/s
UDMA 66
30ns
2
60ns
(1/60ns) x 2byte x2 = 66MB/s
UDMA100
20ns
2
40ns
(1/40ns) x 2byte x2 = 100MB/s
Tip:
To achieve the best performance of Ultra ATA 66/100 hard
disks, a special
80-wires IDE cable
for Ultra ATA 66/100 is
required.
32
