Recommendation to WD hdd for sudden drop of low speed


i have got a 1.5Tb ears hdd faced similar problem.

here are some temporary solution to the slow bug due to drop to PIO state.(at least you could save your data at a faster rate…)

  1. change your hdd configuration to ACHI mode so it will force it to use DMA mode for data transfer

  2. increase your temperature of your hdd to optimum temp of around 30-40+(seems like the temp cannot be too low or it will drop to PIO mode)

  3. change registry to force back to DMA mode

below is the tutorial for forced DMA i copied from one website(

  1. Open RegEdit

  2. Find the following KEY: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ Class{4D36E96A-E325-11CE-BFC1-08002BE10318}\000x

  3. The last four digits will be 0000, 0001, 0002, 0003, and so on.

  4. Under each key, delete all occurences of the following values: MasterIdDataChecksum SlaveIdDataChecksum

  5. Reboot the computer. Windows will now redetect DMA settings.

do check this article for more info about the issue IDE ATA and ATAPI Disks Use PIO Mode After Multiple Time-Out or CRC Errors Occur

and lastly, of course i’m not 100% sure if this will work for all type of problem, but i hope this will help some to at least save their precious data…


Thanks for that, I’ve been puzzling over the fact that my EARS drive has recently slowed down in a big way. A quick check showed it had dropped to “PIO” mode and I’ve now got it back into DMA mode and made the Microsoft-suggested registry change to, hopefully, stop it dropping back again.

You wrote that “i have got a 1.5Tb ears hdd faced similar problem”. Is there a thread somewhere about this as I’m interested in finding out why these drives are reporting timeout/CRC errors and I haven’t found any other mention of it other than your post ?




i didn’t create any thread in this forum before but i have reported and asked about this question is some other hardware forum without any solution in the end… and after much research the above are my findings. It seems the chinese and japan community is more informed in this problem then other community, and if you wan to find this problem in 2ch, try WD 低速病, and you should sources tons of similar problem…


Thanks, I’ll have a look there,