What is DMA ?
DMA stands for “Direct Memory Access”.
As the name refers DMA means tranfer of data between IO and disk without intervention of CPU.
The IO processor gets the control of IO buses along with control buses.
Suppose you have connected your peripheral device, e.g., pen drive to you computer. Now you are copying some data from hard disk to that pen drive.
Now to transfer data, the CPU must have to control that. But using CPU only for copying data is not efficient. Here comes DMA controller.
It takes the charge of data transfer betwen devices and frees CPU for other tasks.
But remember the hardwire should actually support DMA & It can only be enabled or disabled using the OS
The whole process can be divided in the following steps:
1. Open Control Panel from the Metro UI.
2. Search for Device Manager.
3. Click on device manager & open Device Manager (Administrator password may be needed). After opening you will see a screen like the following:
4. Expand IDE ATA/ATAPI controllers.
5. Right-click on any label where “Channel” is present & Click on properties (I have used ATA Channel 0)
6. Navigate to Advanced Settings tab & enable or disable DMA by checking or unchecking Enable DMA & click OK.