Yoga 2 Pro Tablet Mode Extremely Slow on Win 10

[eliavl]

So everyday a new problem arises with Win 10 and the Yoga 2 Pro. After reinstalling Transition, the screen now rotates. Yippee. But now the performance in Tablet mode is so slow it's unbareable. Anybody else with this problem? Thoughts?

[eliavl · Accepted solution]

Ok... seems that disabling a Lenovo service called YMC (through the task manager) completely solves this issue with no negative effects. The service is in charge of disabling the keyboard in tablet mode etc., but it seems that it's redundant in Windows 10 (perhaps Windows controls this itself?).

Disable, if it causes problems enable it again.

[RedSign]

I'm a bit wondered about the fact that you say that the touchpad and keyboard still gets disabled after shutting down the ymc service provided by Lenovo. Stopping that must stop the ability to get into tablet mode automatically (Continuum) and getting the touchpad and keyboard disabled.

I tested this right now on my Yoga 2 Pro and right after stoping the ymc service I was no longer able to get the machine in tablet mode automatically by rotating the screen around and as expected the touchpad and keyboard also are not getting disabled anymore. So everyone reading this you should NOT disable the ymc service.

The ymc service and the associated process ymc.exe is there to tell the system whether it is in laptop or tablet/tent mode which not only disables the touchpad and keyboard in modes other than the laptop one but also let's the DPTF technology from Intel (Dynamic Platform and Thermal Framework) kicking in to throttle your machine. This is done to make better use of your battery because normally the full power of the system is not needed in those touch scenarios.

Unfortanetly as you pointed out right the actual DPTF driver is throttling the system way to strong so that it gets nearly unusable in tablet/tent mode. You are right, disabling the ymc service prevents the system from knowing it is used in tablet/tent mode and therefore the DPTF technology does not throttle the machine. But as pointed out this also prevents the Continuum feature to work and prevents the touchpad and keyboard to be disabled in these touch based use cases.

The only solution imho to prevent the system from beeing slowed down in tablet/tent mode is to disable the DPTF feature in the UEFI setup. This is what I have done until there are better DPTF drivers provided. Note that this will have negative impact concerning the use of your battery power.

The problem with DPTF is known for a long time and covered extensively in this Thread.

[eliavl]

Thanks for the reply. I was also concerned that disabling YMC will leave keyboard and touchpad on, but this is not the case with me, not with some others that disabled YMC (as I read in threads re the same problem in Win 8.1).
Maybe there is something else that takes care of if, either native to Win 10, something in the new version of Lenovo Transitions, or even a hardware toggle in some models. I have no idea, the fact is that it works. I would suggest users to try and see, you can always enable it if it doesn't work.

[RedSign]

But you do know that stoping this service in the taskamager as described stops the service in the running session but it will still be started again after a reboot, do you?

[eliavl]

Yes of course. I changed it in the services menu to "manual" so it doesn't restart upon reboot. I'm not lying, it works on this computer (and I tried it to begin with only after reading in another thread that some had similar experiences). There must be another service that kicks on or some hardware toggle in at least some models.
Again, it doesn't hurt to try, and it might work for some.

[RedSign]

No problem I have never thought you are lying, just wondering that it works for you and would like to know why.

I am using Windows 10 as Windows Insider for many months and reinstalled it quite a few times and this functionality never worked for me without the ymc service running. I would really like to know what's the diffrence between our two machines. Hm.

[carbonunit]

Lenovos DPTF drivers are the culprit for this.  Go into BIOS and disable DPTF and the laptop will behave as it should.

[RedSign]

Thank you carbonunit for your contribution but we are already aware of this as I wrote on Post number 3:

> The only solution imho to prevent the system from beeing slowed down in tablet/tent mode is to disable the DPTF feature in the UEFI setup. 

[eliavl]

Well I was curious about this, so I turned on my Yoga in Bios mode. I flipped the computer to tablet, and guess what - the keyboard is disabled even in the Bios screen. Now, since the Bios runs before windows, as I understand, this must mean that the keyboard disabling function is either a hardware toggle, or implemented through the bios itself. But it certainly kicks in way before YMC or any similar program runs.