How can I change the PIO transmission mode of a hard disk?

How can I change the PIO transmission mode of a hard disk?

Let's talk about how the problem arises. In Windows 2000/XP/2003, there is such a setting: Windows IDE/atapi port driver (atapi. sys) after receiving a total of six timeout or cyclic redundancy check (CRC) errors, the driver will forward the communication speed (transport mode) from the fastest Direct Memory Access (DMA) the mode is step-by-step reduced to a slow DMA mode. If the driver continues to receive a timeout or CRC error, the driver will eventually downgrade the transfer mode to the slowest mode (PIO Mode ). The problem is here! In general, a normal hard disk rarely has timeout or cyclic redundancy check (CRC) errors, but when we use these systems to suspend (also called sleep) after the computer is restored, timeout or CRC errors may occur. Because the timeout value set by the system is 4 seconds, when the system sends a read request to the ATA disk, if the hard disk response time exceeds the timeout value of 4 seconds, a timeout or cyclic redundancy check (CRC) error occurs, however, when the system is suspended (or sleep), the hard disk is in the stopped state. When the computer is restored, the hard disk has a process from stopping to moving, this easily results in a timeout value that exceeds 4 seconds for most hard disk responses. That is to say, when we use a computer to suspend for 6 times, the system will access the communication speed (Transfer Mode) from the fastest Direct Memory. (DMA) Mode Step-by-Step downgrade to a slow DMA mode. If more than six hangs, the driver will eventually downgrade the transfer mode to the slowest (PIO mode ). This is why the Windows system suddenly slows down. Solution: To re-enable the typical DMA or faster DMA transfer mode for the affected device, perform the following operations: 1. Double-click "Management Tools" and double-click "Computer Management "; 2. Click system tools, and then click Device Manager "; 3. Expand the "Ide ATA/atapi controller" node; 4. Double-click the Controller for which you want to restore the typical DMA transfer mode; 5. Click the driver tab; 6. Click "Uninstall ". After this process is completed, restart your computer. After windows restarts, the hard disk controller is reenumerated and the transfer mode of each device connected to the Controller is reset to the default value. However, this only resets the transmission mode of the hard disk device to the default value. When the system is suspended, the system will disable the DMA mode on its own! Therefore, we need to do the following: 1. Click Start, click Run, type regedit, and click OK ". 2. Locate and click the following items in the registry: HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ class \{ 4d36e96a-e325-11ce-bfc1-08002be10318} \ 0001 and HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Control \ class \ {4d36e96a-e325-11ce-bfc1-08002be10318} \ 0002 3. On the "edit" menu, point to "new" and click "DWORD Value ". 4. Type reseterrorcountersonsuccess and press Enter. 5. On the "edit" menu, click "modify ". 6. Type L and click OK ". 7. Follow these steps to exit the Registry Editor: Note: The subkeys listed in the last item "{4d36e96a-e325-11ce-bfc1-08002be10318}" in the Registry above correspond to the primary ide channel and secondary ide channel of a computer with only one ide controller. If your computer has two ide controllers, the numbered sub-items of the primary ide channel and secondary ide channel for each controller are: "0001, 0002, 0003, 0004, 0005, 0006 ......". To check whether the correct subitem is found, check whether the driverdesc value of the subitem contains the string value "Main ide channel" or the string value "secondary ide channel ". The purpose of setting up the preceding registry key is: In Windows, change the timeout value of 4 seconds when the system sends a read request to the ATA disk to 10 seconds. We also implemented a less rigorous work ing policy to reduce the transmission mode in case of timeout errors and CRC errors (from the fast DMA mode to the slow DMA mode, to the PIO mode ). Previously, when the total number of accumulated timeout errors or CRC errors reaches 6, the IDE/atapi port driver (atapi. sys) will decrease the transmission mode. After the preceding registry key value is set up to implement a new policy, atapi. sys only degrades the transfer mode after six consecutive timeout or CRC errors occur. This new policy will greatly reduce the chances of the system reducing or disabling the DMA transfer mode. Now we can safely use the suspended system and high-performance DMA hard disk mode, and there will no longer be a sudden decline in system performance.