Using hdparm - Settings explained
To list the current settings being used for your drive use the command:
This should produce the following output showingthe defualt (lowest) settings:
multcount = 0 (off)
I/O support = 0 (default 16-bit)
unmaskirq = 0 (off)
using_dma = 0 (off)
keepsettings = 0 (off)
nowerr = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 49585/16/63, sectors = 49981680, start = 0
Only the most supported options are listed below. Please view the man page for the more dangerous settings.
Permits the transfer of multiple sectors per I/O interrupt rather than the defualt of one.
Check your "MaxMultSect" setting from your drive's information (above) to find the maximum value.
A setting of 16 is a good value to try first, unless you have a Western Digital drive then should try a setting
of 4 to 8.
I/O support (-c)
IDE 32-bit I/O support. One of the following numbers are used to enable/disable 32-bit I/O support:
0 to disable 32-bit I/O support
1 to enable 32-bit data transfers
3 to enable 32-bit data transfers with a special sync sequence
Note: IDE drives still have only a 16-bit connection over the ribbon cable from the interface card.
Interrupt-unmask flag for the drive. A setting of 1 permits the driver to unmask other interrupts
(eg. one from a network card) during processing of a disk interrupt, this show improve overall system
Note: Use this feature with caution: some drives and controllers do not tolerate the increased I/O latencies
possible when this feature is enabled, resulting in massive filesystem corruption.
Disable/enable the Use of DMA operations for the drive. This option only works with a few combinations of drives
and interfaces which support DMA and which are known to the IDE driver (eg. Intel's Triton chipset).
Best used with the "IDE transfer mode" option.
IDE transfer mode (-X)
This is used in combination with the "-d1" option to enable DMA for the drive. Two settings can be used here:
34 is used to select multiword DMA mode2 transfers
66 is used to select UltraDMA mode2 transfers (for systems which support UltraDMA burst timings)
68 is used to select UltraDMA mode4 transfers (for systems which support UltraDMA burst timings)
Note: An incorrect setting may cause your system to hang.