4-14AcerAltos 21000 System GuideHard Disk Block ModeThis function enhances disk performance depending on the hard diskin use. If you set this parameter to Auto, the BIOS utilityautomatically detects if the installed hard disk drive supports theBlock Mode function. If supported, it allows data transfer in block(multiple sectors) at a rate of 256 bytes per cycle. To disregard thefeature, change the setting to Disabled .Advanced PIO ModeWhen set to Auto, the BIOS utility automatically detects if theinstalled hard disk supports the function. If supported, it allows forfaster data recovery and read/write timing that reduces hard diskactivity time. This results in better hard disk performance. Todisregard the feature, change the setting to Disabled .Hard Disk Size > 504 MBWhen set to Auto, the BIOS utility automatically detects if theinstalled hard disk supports the function. If supported, it allows you touse a hard disk with a capacity of more than 504 MB. This is madepossible through the Logical Block Address (LBA) mode translation.However, this enhanced IDE feature works only under DOS,Windows 3.x, and Windows 95 environments. Other operatingsystems require this parameter to be set to Disabled.