06-23-2016 08:18 PM
I had the same problem and it's really frustrating! Everything in win10 seems good and better than win8.1. But too bad there's no solution. Tried the mtd by Delphis and some others. All can't work. The problem is definitely software, as mentioned by some users since it worked very well in win8.1 bing. I can't say Lenova is solely responsible but both Microsoft and Lenova should try to do a fix. Someone should delete the "solution" since it can't work for most ppl. Lenova staff, can you say something? Or at least tell us your difficulties as to why it can't be fixed? The tablet is quite good for most purpose and I would say this is really disappointing. It should really just be fixed since it's not just a bug - it just can't work!
04-05-2018 01:34 PM
Apparently I'm late to the party but I encountered the same issue with this tablet.
I am still using windows 8.1 and all was fine until the latest update.
The SD card stopped working. The same card that worked fine until the update.
I have downloaded the intel kits from the lenovo website, uninstalled the drivers in Device Manager for all of the intems related to the SD card, with a card already plugged in, and then reinstalled the original Lenovo drivers.
Now it works as before.
I have disabled the optional updates, as the drivers came as optional.
09-08-2018 12:51 PM
In case anyone is interested, this is a known bug the SD Controller embedded in the Intel Bay Trail platform.
It's cataloged as VLT55 by Intel.
Basically, Intel failed to correctly impliment the SD Card 3.01 spec, so devices that use UHS-I/DDR50 mode will fail randomly.
This bug can (and does) occur on any Bay Trail device that doesn't have the workaround implimented. It only affects cards that use DDR50 mode, which are cards rated in the 40-50MB/s read speed range.
There isn't a way to fix this bug, but a work-around for this is quite simple, and can be implimented in either the driver or the BIOS: don't allow the SD controller to opperate in DDR50 mode. If the driver or BIOS forces the controller to fallback from UHS/DDR50 mode to UHS/SDR25 mode or HS mode, the bug doesn't come in to effect. That does mean the SD card speed would be limited to 25MB/s, but it would be stable.
This would be a VERY simple thing for Lenovo or Intel to issue a work-around for. In fact Intel supposedly has the doccumentation available to developers to impliment the work-around.
As Lenovo doesn't seem interested in fixing this (especially on an old tablet like ours) I'm looking in to alternative ways to patch this permanently, but I don't know if it will pan out.
As I mentioned, SD Cards that don't use DDR50 mode are unaffected, so any card that uses a different specification should be fine. Look for cards that are rated for a maximum read speed of 25MB/s or 104MB/s, these cards will use modes that are fully compatible with our hardware.
12-18-2018 08:38 AM
This is very interesting. Finally, we are stuck between Intel and Microsoft... and we have to use old sd card technology...
How can we find detailled specifications about DDR50 or DDR25 ? For Sandisk for example, I can't find these details in order to choose the right sd card, well, one that works in my Yoga Book Win10. And it's independant from capacity (up to 128Go) ?
Such a downgrade...
12-20-2018 02:36 AM
I tried to install manually Win8.1 driver for intel SD host controller device but Win10 can't permit it. It always says that the driver up-to-date is yet installed...
Even if I choose specific option to search the old driver I downloaded and put in a directory in c:\ , Windows says that this driver is unsigned, so I can't install it.
I tried several ways to disable this protection (bcedit.exe with testsignon and disable security check, reboot with start options and F7 key but on my YogaBook the halokeyboard is not actived at this step, GPO modify etc...) but no one works. Windows refuses to install unsigned driver.
I'm in Win10 Pro 1809.
Any solution ?
12-22-2018 11:18 AM
12-22-2018 11:28 AM
12-22-2018 11:37 AM