IDE hard drives basically use 40-pin ribbon cable for connecting to the computer’s motherboard. Only two IDE hard drives can be attached to one 40-pin ribbon cable at a time. The interface runs in parallel within IDE hard drives, sending the data in groups, rather than a single stream of data. This makes the functioning slower because when the data is received in groups at the other end of IDE, the receiver has to wait until entire data is transferred before it can proceed on it. A 4-pin Molex power connection is used to connect IDE hard drives to the computer. The speed of data transfer in IDE hard drives is between 33 MB/s to 133 MB/s. The other disadvantage of IDE hard disks is that they work on FIFO method (first in first out) for handling the commands.
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SATA hard drives use a much smaller 7-pin cable, which allows only one hard drive to be attached to it at a time. Data is transferred through a continuous stream in SATA drives, rather than in groups. This makes the data processing smoother. This sort of hard drives don’t use Molex cables to power but 3.3v line. The data transfer rate in SATA hard disks can range from 150 MB/s to 300 MB/s.
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