Extreme slowdown with battery below 50% ( VN7-792G )

Any apps requiring even moderate processing (like Excel, Word, etc. - gaming would be impossible) become crazy slow when the battery goes below about 50%. Once the slowdown starts, it gets worse and worse until I lose control of the cursor and then need to reboot. If I reboot (still on battery) the machine is slow, but usable - until the slowdown accelerates again.

I have tried every setting available in Windows 10 power / battery management, and nothing helps at all. If the machine is plugged in, everything is fine. Wondering if anyone here is experiencing similar, or if there is a known fix ??? I saw someone else installed Throttlestop 830 app to deal with this - but that's ridiculous to have to do that to be able to use our computers.

It seems most likely something in the Acer Power Management software... Is there any reason not to just disable all those services?

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IronFly

have you already checked the BIOS version on your laptop?

if below 1.09, please update it

https://global-download.acer.com/GDFiles/BIOS/BIOS/BIOS_Acer_1.09_A_A.zip?acerid=636014797032774591&Step1=NOTEBOOK&Step2=ASPIRE&Step3=ASPIRE%20VN7-792G&OS=ALL&LC=en&BC=ACER&SC=PA_6

to check BIOS version:

windows logo key + r

type

msinfo32

check BIOS DATE/Version

check CPU power settings on battery under windows power management too.

starstudio

Hi, thanks - The BIOS version is 1.02, date is 9/25/2015. So hopefully that's the problem. A bit surprising to me that the Acer Care Center doesn't check for outdated BIOS.

(I have already changed the CPU settings, etc. in advanced power options and that had no effect.)

Just updated BIOS. Keeping my fingers crossed... Will post the results here in the next day or two.

starstudio

Hi, unfortunately the BIOS update had no effect Smiley Sad .

Here's a pic of my settings and CPU state while this is happening. Unfortunately, with my machine, it doesn't just slow down a bit - it becomes totally unusable. (It is throttling the cpu to a steady 780-790 Mhz and happening when ny battery level gets to precisely 40%, so I realize now that this is EXACTLY the same problem as this poster here: http://community.acer.com/t5/V-and-VN-Series-Laptops/Acer-V15-Nitro-Gets-Slow-on-Low-Battery/m-p/464952/highlight/false#M13207.) Any ideas?

I really don't want to rely on ThrottleStop, as the poster above did (successfully), because it could stop working at any time with a MSFT or an Acer update.

slow.PNG

starstudio

I've done quite a bit of research into this issue now. The slowdown behavior seems most prevalent to Skylake based laptops from Lenovo, Acer, and MSI. It is caused by a combination of Intel's, Microsoft's, and manufacturers' firmware/software. Basically it's intentional core-parking and thermal throttling at an overly conservative level. I did two things to take control of my CPU back which worked great ON THIS PARTICULAR MACHINE:

1. (If you aren't proficient in Regedit - skip this one - and go straight to Throttlestop in 2. It will get you most of what you want).

Did a couple of registry tweaks. These both just unhide user options that have been hidden in the regular Power Plan's (Advanced) settings menus. The first command unhides Intel's hardware resident Core Parking and the 2nd unhides the Windows OS-managed core parking. Type these into an elevated command prompt (no reboot required):

powercfg -attributes SUB_PROCESSOR 0cc5b647-c1df-4637-891a-dec35c318583 -ATTRIB_HIDE

powercfg -attributes SUB_PROCESSOR 8baa4a8a-14c6-4451-8e8b-14bdbd197537 -ATTRIB_HIDE

After unhiding, you can set these as you would like in your Power Plan's Advanced settings. In fact - immediately go there to check if the 2 new options show up. If they didn't - immediately undo your registry changes by changing the -ATTRIB_HIDE to +ATTRIB_HIDE and rerun the commands. Then figure out where you went wrong - check both these links for very detailed procedures:

Disable_CPU_Throttling_in_Windows

Core Parking and Skylake - Scroll about 1/2 way down page to :"Processor performance autonomous mode (Enable/Disable)"

Once unhidden, setting my "Processor performance core parking min cores" to 100%, and Processor Performance Autonomous Mode to DISABLED - the PC response improved enough that it still slowed on intensive software, but was usable. Of course, this decreases battery life a bit.

2. Bit the bullet and installed Throttlestop. It's a great piece of software that does everything it's supposed to do and is very well thought out. My only concern is that some update to Windows 10 or change in Intel firmware could blow it up. But we don't have much choice here...

On battery now, I have set Throttlestop to basically pin my cpu at about 1.8 Ghz (using Set Multiplier). I set my Processor performance core parking min cores to 50% (see above), and in Throttlestop Disabled Turbo to keep heat down, Disabled Power Saver (which is the INTC/Microsoft hidden setting that throttles your CPU), and unchecked ProcHot. This gives me good responsiveness and does not generate excessive heat. But a great feature of Throttlestop is that you can set an overheat "alarm" which will auto switch to a lower power setting if the cpu exceeds a certain temp threshold.

(Obviously this is not a gaming setting - it's for cpu intensive work like large excel spreadsheets, audio/video editing, etc.) Here's what it looks like:

As usual, if you do any of this - create a System Restore point beforehand. And also monitor your machine for excessive voltage/heat until you have confidence in your settings. Throttlestop can add a Mhz/CPU monitor on your taskbar!