Review: Ultra-ATA/133

Specifications

Maxtor's step from Ultra-ATA/100 towards Ultra-ATA/133 is not very spectacular from a technological point of view. Concerning the specifications basically the timings changed. Both the data width of 16 Bit and the 40-pin plug are identical with the present ATA standards. At the moment the T13-Committee is working on the inclusion of Ultra-ATA/133 into the official ATA/ATAPI specifications.

Ultra-ATA/133's higher data transfer rate of 133 MBytes/s (calculating on base 1024 that is 127.2 MBytes/s) is achieved by shortening the cycle time from 40 ns (ATA/100) to 30 ns. Within this window of time the interface transfers its data in burst mode with the falling and the rising timing edge. This DDR procedure has already been used since Ultra-ATA/66.

Survey of Ultra-ATA standards

Mode

Transfer Rate

Cycle Time

Cable

The transfer rates are calculated on base 1000.

ATA/133

133 MBytes/s

30 ns

80-core

ATA/100

100 MBytes/s

40 ns

80-core

ATA/66

66 MBytes/s

60 ns

80-core

ATA/33

33 MBytes/s

120 ns

40-core

For Ultra-ATA/133 operation you need - as well as for Ultra-ATA/66 and /100 - an 80-core ribbon cable. Each signal line and data line is assigned to an own mass line here. That is necessary to reduce "crosstalk" between the signal lines during high frequencies. In case of connecting a 40-core IDE cable the interface will automatically switch over to the much slower Ultra-ATA/33 operation mode.