FAQ: What's all this about DMA?

[blutach]

What's all this about DMA?

DMA, if on, can greatly speed up communications between your PC and its hard drive and DVD/CD drives.

The following assumes your hard drive is on the primary channel and the CD/DVD drive is on the secondary.

To check if it is on:

1. Right click on My Computer
2. Select Properties
3. Click on Hardware
4. Click on Device Manager
5. Double click on IDE ATA/ATAPI controllers
6. Double click on Primary channel
7. Click Advanced Settings and check it says DMA if available and is set to Ultra DMA, mode 5.
8. Do the same for the secondary channel -- it should be Ultra DMA, mode 2.

Don't worry if it says "Not applicable" - it means there is no device connected to that port.

The following diagram shows my primary channel (I have 2 hard drives connected):




If your PC doesn't have DMA enabled, the easiest way to re-enable it is to remove the channel and reboot. Windows will then automatically reinstall it and reset the counters that deactivated DMA in the first place.

To remove the channel:

1. Right click on the relevant channel in Device Manager (you know how to get there - follow steps 1 thru 5 above )
2. Click on uninstall
3. Reboot
4. When you have rebooted (and the drive and been recognised by Windows again), go back to Device Manager and change the setting to DMA if available.
5. Windows NT/2000 users reboot again. XP users, you're good to go.

This article is a very good tutorial on DMA. I advise you to read it.

[cynthia]

To switch the master/slave position with your burner and reader can solve it.

Credit: eelco

Also try to make an update of your computers BIOS.

Credit: greenjanek

[cynthia]

Drive does not have a DMA check box

Problem:

When you view properties for drives in Device Manager, the drive may not have a DMA check box.

Cause - for Windows Me and 98:

This issue can occur if a non-ATAPI driver is controlling the drive. For example, SCSI drives do not have this check box, and drives attached to third-party IDE controllers requiring a special miniport (such as the Promise Ultra Wide 66 with the ULTRA66.MPD driver) also do not work.

Solution:

To resolve this issue, use the Esdi_506.pdr file:

1. Click Start, point to Settings, click Control Panel, and then double-click System.
2. Click the Device Manager tab, double-click Hard disk controller, click the appropriate hard disk controller, and then click Properties.
3. Click the Driver tab, click Update Driver, and then click Next.
4. Click Specify the location of the driver (Advanced) to select the driver that you want to use, and then click Next.
5. Click Display a list of the drivers in a specific location to select the driver that you want to use, and then click Next. 6. Click the driver that matches the date of your operating system, and then click Next. Note that for Windows 98 the date is 5/11/1998, for Windows 98 Second Edition the date is 4/20/99, and for Windows ME the date is 6/8/2000.
7. Click Next, click Finish, and then restart your computer.

Credit: Microsoft

[jmet]

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