I have 7 WD RED 4TB (WDC WD40EFRX-68WT0N0)
6 of them are showing the expected performance in reading and writing speeds.
1 is ony able to deliver write speeds between 12 MB/s an 27 MB/s.
This is in 3 different systems: Supermicro A1SAM, ASUS P9A-I and a Asus P8Z77 (3770K).
After one week of surface tests no problems were discovered.
When doing a little bit of research I stumbled across the Windows Disk Write Caching.
On 6 out of 7 Disks this “feature” was enabled.
On the slow disk it wasn’t.
So I thought: Lets give it a try and enable this option.
Right-click My Computer , and then click Properties.
Click the Hardware tab, and then click Device Manager.
Expand Disk Drives.
Right-click the drive on which you want to turn disk write caching on or off, and then click Properties.
Click the Policies tab.
Click to select or clear the Enable write caching on the disk check box as appropriate.
Click OK.
But Windows 8.1 Pro wont let me…
Not on any of the 3 different machines.
Instead I receive the following error (translated from German)
Windows could not change the write-caching setting for the device. Your device might not support this feature or changing the setting.
Any solution for this? A 3rd party programm perhaps ?
Or should I try to RMA the drive because the option can not be enabled?
After I read this, I looked at a number of my drives, both WDC and SSD. All enable write cache (under W-7, though). Then I ran Lifeguard and noticed that there is no statistic for caching (WDC should add this, I think). It seems to me that your odd drive has some problems. I suggest talking to WDC support.
Bit #5 of word #82 of the Identify Device information block indicates whether “the volatile write cache is supported”.
Bit #5 of word #85 of the Identify Device information block indicates whether “the volatile write cache is enabled”.
Bit #1 of words 119 and 120 indicates whether “the Write-Read-Verify feature set is supported/enabled”.
If Write-Read-Verify is enabled, then this would result in slower writes because there would need to be two revolutions of the platters for each write.
Hello, I’m currently experiencing the same problem on all of my 6 WD40EFRX-68WT0N0.
My drives previously had write cache enabled in windows for roughly one year now, I know for sure! But just recently I realized very slow write performance (up to only 20-25 MB/s) and found the write cache being disabled on all of these disks. It is not possible to enable the write cache from windows device manager any more (same error message/behavior as mentioned above).
SMART info with HD Sentinel and CrystalDiskInfo shows:
Drive is HEALTHY, no SMART errors at all
Write-cache supported, but DISABLED
Write-Read-Verify DISABLED
A test with WD LifeGuard Diagnostics first of all only detects 5 of my 6 drives. But it did not reveal any problems (I’ve performed a QUICK test only. Not tested for bad sectors, as this takes too long and I do not assume that all 6 drives have gotten bad sectors at the same time while SMART does not show anything)
Now I first thought it might be a Windows problem, but it is not. Booted with current Ubuntu linux 14.04 and checked status wtih hdparm and smartctl. And the result is again:
Drive is HEALTHY, no SMART errors at all
Write-cache supported, but DISABLED
Write-Read-Verify DISABLED
Now the funny thing is if I use hdparm to try to enable the drive’s write cache I get the following:
/dev/sda: setting drive write-caching to 1 (on)
write-caching = 0 (off)
I’ve even already tried different controllers (onboard/extension):
Intel ICH7
Marvell 92xx
Marvell 94xx
Asmedia 106x
The problem is identical for all types! So I strongly assume it has nothing to do with the controller.
What is going on here? Any ideas? Is it necessary to contact WD support? Thanks in advance for any help.
I have been suffering from the same problem, and it is solved now.
As someone have mentioned in another thread, drive write cache is being disabled by some RAID devices, notably Adaptec. After that, it cannot be reenabled just by ATA command, which is what hdparm -W does. To reenable write cache, you need to use SCT command:
smartctl -s wcache-sct,ata,p /dev/sdg
smartctl 7.2 2020-12-30 r5155 [x86_64-linux-5.15.0-48-generic] (local build)
Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF ENABLE/DISABLE COMMANDS SECTION ===
Write cache SCT Feature Control is set to: Controlled by ATA (persistent)
