How is ATA different from DMA for hard drives?

DMA stands for Direct Memory Access, which means "Direct Memory Access". ATA is IDE, ATA is IDE's more detailed technical specifications, and IDE is just a name for ATA in the field of manufacturing and sales. An IDE hard drive is a hard drive that uses ATA protocols, technologies, and interfaces.

ATA was developed by the National Committee on Information Technology Standards (NCITS) T13 Technical Committee (formerly T10 Technical Committee, later transferred to T13) of the American National Standards Institute (ANSI). It is correctly described in the draft of Serial ATA on its official **, that is, it is the Serial version of ATA ATAPI. Therefore, hard disks that use the Serial ATA interface are still IDE hard disks.

In the future development plan of IDE RAID cards, AMI has also prepared IDE hard disks with Serial ATA interface, that is, IDE hard disk controllers with Serial ATA interface. This shows that ATA 66 represents a hard disk with an IDE interface, and the transfer mode used is DMA 66. The DMA technology is exclusive to the hard disk of the IDE interface, so both ATA 66 and DMA 66 are talking about the same thing.

One hard drive, one memory!

1. DMA is direct memory access. This refers to a high-speed data transfer operation that allows data to be read and written directly between external devices and memory, neither through the CPU nor without CPU intervention;

2. The entire data transmission operation is carried out under the control of the DMA controller;

3. In addition to doing a little processing at the beginning and end of data transfer, the CPU can do other work during the transfer process. In this way, most of the time, the CPU and I/O are in parallel operation. Thus, the efficiency of the entire computer system is greatly improved;

4. DMA is under the control of specialized hardware, grip keys, such as to achieve high-speed peripherals and the main memory between the automatic batch exchange of data to minimize the input of CPU intervention or.

ATA hard disks generally use the IDE interface, which is divided into PATA hard disks (i.e., Parallelata, parallel ATA hard disk interface specification) and SATA hard disks (i.e., Serialata, serial ATA hard disk interface specification).

SATA (Serial ATA) port hard disk, also known as serial port hard disk, is the trend of PC hard disk in the future. In 2001, the Serial ATA specification was formalized by the Serial ATA Committee composed of Intel, APT, Dell, IBM, Seagate, and Maxtor. In 2002, although the Serial ATA related equipment was not officially marketed, the Serial ATA Committee had preemptively established the Serial ATA specification.

Distinguish. Distinction between pata and sata.

The full name of PATA is Parallelata, which is the parallel ATA hard disk interface specification, which is no longer common. The size of the PATA hard disk interface has a very glorious history, and it has developed from ATA33 66 to ATA100 133 to the highest ATA150 today. The full name of SATA hard disk is Serialata, that is, the interface specification of serial ATA hard disk, which is a common type at present.

At present, the typical write speed of the PATA100 hard drive is 65MB s, while the first generation SATA hard drive has a write speed of 150MB s, and the second generation SATA hard drive has a write speed of up to 300MB s, which is exactly twice the speed of the first generation. Similarly, the third-generation SATA hard drive has a maximum write speed of 600MB s, which is twice as fast as the second-generation drive. The emergence of the SATA hard disk interface specification is actually to replace PATA, just like DDR replaces SDRAM.

Serial. ata

It is the connection cable between the hard disk and the motherboard.

So is sata. SATA transfer speed is faster than ATA. And it's basically sata's now.

More than 4000 computers can be played.

1 is all very old problem. Now new hard drives don't have this mode anymore.

DMA, which stands for "Direct Memory Access", is a data exchange mode in which data is accessed directly from the memory without going through the CPU. In PIO mode, the data transfer between the hard disk and the memory is controlled by the CPU; In DMA mode, the CPU only needs to issue instructions to the DMA controller, let the DMA controller handle the data transmission, and then feedback the information to the CPU after the data is transmitted, which greatly reduces the CPU resource share. The difference between DMA mode and PIO mode is that DMA mode does not rely too much on the CPU, which can greatly save system resources, and the difference in transmission speed between the two is not very obvious.

DMA mode can be divided into Single-Word DMA and Multi-Word DMA, of which the maximum transmission rate can be achieved is only.

The old hard disk is a PATA interface, and there is a DMA transfer mode, and the current hard disk is a SATA interface, which uses the transfer mode.