|Which retail mboard model or brand name system model are these drives connected to? |
Check your SATA data cables. The connector on each end should "latch" into the socket on the drive and on the mboard, or on the drive controller card - it should not move when you merely brush your hand against it near the socket - if it does, mere vibration can cause a poor connection of it - use another SATA data cable that does "latch", or tape the connector in place.
(There is a slight projection or bump on one side of the outside of the connector that "latches" it into the socket - it's easily broken off or damaged)
The same thing applies for the SATA power connection.
Take a look in Device Manager at the Properties for the drive controllers to see whether Windows has both drives set to the max UDMA mode they can use on your particular mboard.
A SATA or SATA II drive in an IDE compatible mode (that's set in the bios) - mode 6 in Windows (UDMA 133)
SATA (150 mb/sec max burst speed) drive in SATA mode (that's set in the bios) - mode > 6 ? in XP ?,
SATA II (300 mb/sec max burst speed, if both
the mboard and the drive supports that) drive in SATA mode - a mode higher than that ?
If the Hitachi drive is set to PIO mode, try setting it to DMA if available, save settings, then go back in and see if it's in it's proper mode.
If those settings in Windows are fine....
The max. sustained (and max burst) data transfer rate is just that - a maximum. The drive does not always use the maximum rate , depending on what is required.
You can only compare the rate when what is being done is identical.