Source
r/Surface•
xobs

How do you keep a SB2 from slowing to 400 MHz?

I just got my SB2 a few weeks ago, and it's working great! It's a fantastic machine, and I'm really liking it. Except for the part where it slows down after a while.

If I open Task Manager's Performance tab, I can keep track of the CPU speed. It starts out reasonably high, depending on the mode the machine is in (Recommended, Better Performance, Best Performance), but after a minute or two it always slows way down and settles at a speed of 0.4 GHz. Naturally, when it does this the mouse gets really slow.

My workaround is to click on the battery icon and change the slider. It doesn't matter if I go from Best Performance to Recommended, go the other way, go midway in between, as long as I change the slider the CPU speed will pop back up to something over 1.2 GHz. Then after another minute or two, it will slow back down.

Has anyone else encountered this problem, and what can be done to fix it?

edit: This is happening even when doing something that should need more than 400 MHz. For example, during a Skype call.

I've just discovered ThrottleStop, which seems to solve the problem. When I first opened it the "TDP Throttle" radio was ticked, and the reason was "PL2". Just having it open and turned off seems to fix something. I'll do some more research, and now I know what to look for.

Posted Jan 29, 2018, 10:21 AM UTC · edited

1217
surface_bookAsusFlip + SB i5 8/256 w/dGPU•

I think there is a bug somewhere. I have been noticing a different computer, an ASUS, with an 8th gen i7 also slowing to 400MHz. It's hard not to notice. It's not exactly the same chip, so either the problem is generic to Intel or Windows.

5
Osmirl•

I'm not 100% sure about this one cause I never needed it, but I think there is a way to lock some cpu frequences in the registry.

4
draconis183•

I experience this on sb1 too. The problem is real. I notice it if edge has been open a long time or any office 365 application. I always just rebooted.

4
binaryvisions•

If you're just watching task manager, an idle machine should drop down to low CPU speeds.

When it drops down, launch an application - you should see it spike right back up to normal frequencies.

3
xobsOP•

Correct, yet it's happening when the machine isn't idle. For example, Skype video slows way down because, according to Task Manager, the cpu has slowed itself to 400 MHz which isn't enough to decode video. So to work around it I have to keep changing the power profile every minute I'm on a call.

3
Cofet•

Gerbil blood sacrifice

2
azur879•

Isnt this a feature to save battery. It will go up when needed

2
xobsOP•

Except it's not doing that. It settles down to 400 MHz during Skype calls, compiles, and even just opening up Task Manager.

2
zab16Surface Book i7 512GB w/ dGPU•

Yeah I'm pretty sure the clock speed changes dynamically as needed and keeping it raised continuously will only just waste more power.

1
fearfulhorse•

Please, please, please, file something on the feedback hub. I've been having this same issue and I'd like for more ppl at MSFT to realize this is a (relatively) major problem.

2
tapthrow•

I still get this on my SB2 but it happens on my XPS 15 as well. I have the same symptoms but yes toggling the battery/performance will make it unstuck for a short while.

2
ultimahwhat•

In Windows Power settings, if you make your way into additional settings or whatnot, there is an option to set the minimum and maximum cpu speed as a percentage of the advertised clockspeed (0-100%). Hope this helps!

1
xobsOP•

Do you mean the power profiles setting? Weirdly, on my SB2 there is no option for CPU speed. Brightness, HDD sleep time, and display sleep are all there, but no option to adjust the CPU frequency.

1
ultimahwhat•

You are correct. I just checked on my Surface 3, and that setting is not there. It is there on my desktop system that I built. Not sure if it's a mobile CPU deal or whether MS locked it on the Surface line.

1
alirezaektSB2•

i have the same problem have you found any solution?

1
xobsOP•

I just posted a new update, but the issue is thermal. The only workaround I've found is to get a cheap USB fan and point it at the back of the unit. This fully works around the problem.

2
fightclubdevil•

CPU speed get throttled down when overheated. Does the computer feel really hot before cpu speed decreases? Of yes consider some sort of aftermarket cooling system.

0
xobsOP•

According to the sensors, it's at 60 degrees.

2
mixermixingSP2 i5/8/256•

Have you tried a reset to factory defaults?

-1
xobsOP•

Not yet. It's a fresh install, only a few weeks old, so I'd rather not do that.

1