windows xp 檢查和設置DMA模式

[psac]

Check and Set DMA Mode
To view the DMA mode used by your drives, you need to open the Device Manager (Control Panel > System select the Hardware tab and press the Device Manager button) and view the properties of the IDE ATA/ATAPI controllers. Double-click on the IDE ATA/ATAPI controllers entry to expand it, the right-click on the Primary IDE Channel and Secondary IDE Channel entries (one at a time) and select Properties from the menu.



Now select the Advanced Settings tab. The Current Transfer Mode will be listed. To change, click the selection arrow on the Transfer Mode drop-down box. Remember, DMA is best, but sometimes a CD-ROM won't function properly in DMA mode. So if you find that your CD-ROM uses PIO mode, you can check to see if it will use DMA, but if you experience problems, change it back.



If you want to know which devices (hard drive or CD-ROM) are connected to a specific channel, on the View tab in Device Manager, select Devices by connection. If needed you can expand the entries by clicking on the + sign in front of the entry.



You can even see which drive partitions are on which physical hard drive (provided you have partitioned your hard drive) by right-clicking the listing for the drive you want to examine in detail, select Properties and select the Volumes tab and click the Populate button.






UDMA66
According to Microsoft, UDMA66 mode is disabled by default on a Windows computer with an Intel chipset that supports UDMA66. To enable UDMA66 mode you need to:

Make sure the device supports UDMA66 mode
Use a 80-pin IDE cable with the proper pin cut
Add a registry key
To add the registry key:
Start the Registry Editor
Go to HKEY_LOCAL_MACHINE \ System \ CurrentControlSet \ Control \ Class \ {4D36E96A-E325-11CE-BFC1-08002BE10318} \ 0000 \
Right-click an empty space in the right pane and select New > DWORD Value
Name the new value EnableUDMA66
Double-click this new value, and enter 1 as it's Value data
Close the registry editor
Restart Windows for the changes to take effect
When you restart your computer, the UDMA66 will be enabled if it is supported by the hardware.