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How to enable or disable Direct Memory Access in Windows 7

Updated: Category: Performance & Optimization
Author: Member Level: GoldPoints: 25

Direct Memory Access (DMA) is one of the features which allows hardware devices to access the memory without intervention of the CPU so that data can be directly transferred between memory and the device. This article explains how to enable or disable DMA in Windows 7 computer.

How to enable or disable Direct Memory Access in Windows 7

Direct memory access or DMA in short is a feature which allows some hardware devices in your computer like CD/DVD drives or Hard disks to transfer data directly from or to the memory without using the Processor. This will reduce the overhead on the processor and the processor can be utilized for some other work. Wihtout DMA, the processor has to be fully occupied for the complete duration of the data transfer which is not desirable.

DMA feature is normally enabled by default in Windows 7 for the devices like hard disks and CD/DVDs. If the device is not installed properly, you may need to enable DMA manually for such a device. Let us see how we can enable or disable DMA in a Windows 7 computer.

You should login as Administrator to perform the following steps.

  • Click on Start button and click on Control Panel.
  • Now you will see the window related to Control Panel. Now click on System and Security. Click on Device Manager under System. See a screen shot below.
  • Screen shot of selecting Device Manager in Control Panel in Windows 7

  • Now you need to double click on IDE ATA/ATAPI controllers.
  • Now you will see a list of items under IDE ATA/ATAPI controllers. For each item which has a word Channel as a part of its label, you must right-click on it and select Properties.
  • Now you will see the Properties window. Click on Advanced Settings tab. Under Device Properties, you will see a check box labelled 'Enable DMA'. Select this check box or clear the check box either to enable DMA or disable DMA and then click on OK button. See a screen shot below.

  • Screen shot of enabling DMA in Windows 7

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    Responses to "How to enable or disable Direct Memory Access in Windows 7"
    Author: Bagby  08 Jul 2011   Member Level: Bronze   Points : 1
    This option does not appear for PATA drives on a system that supports them. The option appears only for SATA drives.

    How do you enable DMA for parallel ATA drives? (That would be the Standard Dual Channel PCI IDE controller in your display. There is no evident way to enable DMA on those controllers, which is where it's most needed (because they are slower drives, usually.)

    Author: Bharath  08 Jul 2011   Member Level: Gold   Points : 1
    Hi Raghav,

    This is really very nice article from you about direct memory access in windows 7. Nice informative article from you. It is valuable one.

    Guest Author: Dennis Lew   17 Mar 2013
    What happens if no entry shows anything with "channel"?

    Guest Author: INF_11   07 Aug 2013
    If I instal drivers from manufactured CD, I don't have any "ATA channel".

    But, if I don't install those drivers (and let Windows to install some default drivers instead), its okay, I can finally see ATA channels.

    If you already installed your CD drivers, just right click "Intel ..... ATA controllers" (or AHCI controllers if u have AHCI) in device manager, press uninstall, and check remove drivers. (and reset pc).


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