man hdparm, tamo sve lepo pise, ali ajde opet:
-c Query/enable (E)IDE 32-bit I/O support. A numeric parame-
ter can be used to enable/disable 32-bit I/O support: Cur-
rently supported values include 0 to disable 32-bit I/O
support, 1 to enable 32-bit data transfers, and 3 to enable
32-bit data transfers with a special sync sequence required
by many chipsets. The value 3 works with nearly all 32-bit
IDE chipsets, but incurs slightly more overhead. Note that
"32-bit" refers to data transfers across a PCI or VLB bus
to the interface card only; all (E)IDE drives still have
only a 16-bit connection over the ribbon cable from the
interface card.
i
-u Get/set interrupt-unmask flag for the drive. A setting of
1 permits the driver to unmask other interrupts during pro-
cessing of a disk interrupt, which greatly improves Linux's
responsiveness and eliminates "serial port overrun" errors.
Use this feature with caution: some drive/controller combi-
nations do not tolerate the increased I/O latencies possi-
ble when this feature is enabled, resulting in massive
filesystem corruption. In particular, CMD-640B and RZ1000
(E)IDE interfaces can be unreliable (due to a hardware
flaw) when this option is used with kernel versions earlier
than 2.0.13. Disabling the IDE prefetch feature of these
interfaces (usually a BIOS/CMOS setting) provides a safe
fix for the problem for use with earlier kernels.
