Can not turn on write caching on SSD in Windows 10

Question

I am just installed Win 10. I have 4 SSDs in my installation. Only for one of them I can not turn on write caching. For the other three all is fine.

In the very same PC for the very same 4 SSDs the previous Windows 7 installation enabled the write caching for all the 4 SSDs.

This drive obviously is very slow now, approx tenth time slower than the other three.

Solution

Try this: right click on that SSD in Device Manager, choose Uninstall, this is to remove the write cache preference Windows remembered for that drive.

Then fully shut down the computer (not just restart/reboot), even better disconnect the PC (or the SSD) from its power cable, this is because ATA drive settings are (always, AFAIK) volatile to power cycles, and most drive have write cache enable by default.

Finally connect everything as before and start the computer again and see.

In case it's still disabled (most likely because your drive has the write cache disabled by default), see if you can use HDD Guardian (a GUI of smartmontools in Windows) to adjust the cache setting at all.

Note that this should only be considered as a workaround or used for testing/checking. Since adjusting, this way Windows will not be aware that the disk has write cache enabled, which can cause you data loss. Also, since the setting is volatile, you need to reinforce it every time after booting your PC from cold.

(FWIW, HDD Guardian, or smartctl behind the scene, uses SCSI ATA PASSTHROUGH to identify and adjust the setting instead of SCSI MODE SELECT)

Comments

[magicandre1981]

to which SATA controller is it connected? Try to install the manufacture sata drivers and don't use the internal standard SATA/AHCI driver from Microsoft

[g.pickardou]

Thanks. I do not think it is disabled by default as it was working properly for 3 years under Windows 7

[Tom Yan]

The other case that you still see it as disabled after the uninstalling trick could be because Windows cannot even read drive's the setting. However, if your drive really has write cache enabled by default (just like most other drives), you should at least get the speed you expected, and probably see that the setting is enabled in HDD Guardian. In such situation, there could be data loss. Then you should figure a way to fix Windows, installing AHCI driver from chipset vendor (e.g. Intel RST) as @magicandre1981 suggested is probably your best bet.

[john]

Will this method work to enable write caching on a thumbdrive? I cannot get a 128 gb san cruzer glide thumb drive to allow write caching.

[Tom Yan]

@john I don't think most thumb drives have write cache in them, so no; with that said, OSes usually buffers the writing to them with RAM; that's what the "Removal policy" refers to