Fault performance:
Many people's optical drives or hard drives (especially DVD RW) appear slower (the above refers to IDE devices), the response time becomes longer, and the corresponding IDE channel is found after entering the device lighter. The "current transmission mode" turned out to be "PIO" mode (13. 3 Mbps or less), which made the transmission rate of the IDE device limited on the interface and could only be burned at a low speed. Manually changed to "DMA", but after rebooting, it was found that the setting did not take effect and "Current Transfer Mode" is still "PIO" mode.
Fault reason:
The system's IDE/ATAPI controller driver (Atapi.sys) receives 6 times of timeout or Cyclical Redundancy Check (CRC) error after the cumulative operation. The transmission mode will be automatically reduced by one level. If the timeout or CRC error continues to be received in the future, the final transmission mode will be reduced to the most PIO mode. After we use the system's "wait" or "hibernate" function, the startup speed of the hard disk and other devices is slow when recovering, and it can not respond to the system read request within a certain period of time, which will cause a timeout or CRC error. This will cause the transmission mode to automatically decrease after multiple "waiting" or "shaping".
Solution to the fault:
Execute "regedit" in "Start", "Run" to open the registry editor, "0001" in "HEKY_LOCAL_MACHINESYSTEMCurrentControlSetControlClass{4D36E96A- E325-11CE-BFC1-08002BE10318}" or Find "MasterdDataChecksm" or "SlaveldDataCheck" in "0002" and delete it. After restarting, Windows will recalculate the cumulative number of timeouts or CRC errors. At this point, you can change the "Transfer Mode" of the corresponding IDE channel back in "Device". DMA ".
How to prevent the reduction of the transmission mode?
1, the best way is to upgrade the Windows XP version to SP2, SP2 patch package contains a patch to solve the problem.
2 If you are using Windows XP SP1 or Windows 2000 operating system, open the registry editor, under "HEKY_LOCAL_MACHINESYSTEMCurrentControlSetControlClass{4D36E96A- E325-11CE-BFC1-08002BE10318}", add "DWORD value" to all "000X" items, enter ResetErrorCountersOnSuccess "And press Enter, double click on him to change its value to "1" and press Enter. After the modification, only when the contact has 6 timeouts or CRC errors (previously accumulated 6 times), the system will reduce the transmission mode, greatly reducing the chance of this problem.
There is another situation with this problem, which I have encountered recently, that is the channel conflict caused by the compatibility problem.
My Sata hard drive and ide hard drive have this situation. No matter how I set up Bios or install the driver, I can't solve it. I can only read the files of the Sata hard disk. When writing data to the Sata hard disk, the event record. A record of "The driver detected a controller error for deviceharddisk..." appears in the device. Finally, I couldn't help but buy a sata raid card and circumvent the Sata interface on the motherboard.