I've had this PC running the same way for about a year now (everything working fine) in the past week i noticed that 1 of my 4 hard drives started going really slow.
I checked all my IDE Channel and realized that the hard drive had changed to PIO Mode 4. I select it and check the 'Enable DMA' box and hit OK. the properties dialog closes but when i reopen it it's set back to PIO Mode 4.
Any ideas?
It should not be any slower on PIO 4 than it is on any DMA setting, they are capped at the same rate.
Ultra DMA would be different, doubling the transfer rate.
Could you help us out by:
1. Filling out your system specifications entirely?
2. Telling us if you were doing anything when this happened?
Enabling DMA would make it Ultra DMA Mode 5 like the rest of my hard drives. If i uncheck any of my other 3 it changes it to PIO Mode 4 and i can recheck to make them Ultra DMA Mode 5 again. It's just this 1 hard drive that won't let me.
I haven't been doing anything differently these past couple weeks then i have for the last year. I hardly even use the hard drive, it's mostly for storage.
I've tried uninstalling the device driver, rebooting and reinstalling it and its still on PIO mode.
Check your system logs for errors on the device, particularly, ATAPI timeouts or CRC errors. In the latter case it may be a bad controller or cable or disk circuitry. If it is just timeouts this fix below might work.
Windows counts the number of times there are errors on a drive and if it exceeds a threshold, it will drop the drive down to PIO mode. You can uninstall the controller and it will redetect it and put it back in UDMA mode. However, the problem may reoccur (e.g. if it takes too long for the drive to spin up several times). I had this problem in XP and used the ResetErrorCountersOnSuccess registry fix in the following XP article and the problem went away for good:
IDE ATA and ATAPI disks use PIO mode after multiple time-out or CRC errors occur
Note the same registry key in the article is still valid in Windows 7. I assume the added key will be recognized in windows 7 but maybe that has changed and the fix may not work in that case.
- Gene
i've had this problem with XP years back too and that exact fix is how i got it working. I just tried it now and it seems to be working, it let me change it to Ultra DMA mode now.
Still lags a bit at times, but i'm guessing thats becuz it keeps getting errors/timeouts but keeps reseting it with ResetErrorCountersOnSuccess.
Are these SATA drives?
Which Western Digital drives are they?
Do you have AHCI enabled? - AHCI : Enable in Windows 7 / Vista
Have you run Western Digital's Data Lifeguard Diagnostic test for Windows? - WD Support > Downloads > SATA & SAS > WD Caviar Black
All my drives are Sata yes.
The one having this problem is a WD Caviar Green 1.5TB Sata Drive (WD15EADS)
No AHCI is not enabled.
I just ran the quick test for the drive with Diagnostic tool, then i got this https://i.imgur.com/owDPv.png
all the SMART Status things are passed for the hard drive though.
Oh, that does not sound good. I had my main WD drive fail the short test and pass the long and it turned out to be a bad sector. The good news is that once I got it mapped out the drive has been great for over a year.
If you have scheduled dfrag, then turn it off, else you can corrupt many files. Then try repairing it with the western digital utilities (the bootable DOS one). You can also try chkdsk /r.
http://support.wdc.com/product/downl...sid=30&lang=en
Good luck.
- Gene
Is drive 3 the one that reverts back to PIO Mode 4?
Anyways you may want to replace that drive, or at the very least move your critical files off it till you sort it out.
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