Guolin Cheng said:
Then how to increase PCI IDE disk speed through adjusting PCI bus
You don't. To quote ide.c:
* ide_system_bus_speed() returns what we think is the system VESA/PCI
* bus speed (in MHz). This is used for calculating interface PIO timings.
* The default is 40 for known PCI systems, 50 otherwise.
* The "idebus=xx" parameter can be used to override this value.
* The actual value to be used is computed/displayed the first time through.
In 99% of the cases idebus doesn't need to be changed.