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th3l34sh
12-19-2014, 10:06 PM
I just got my G751JT-CH71 and this thing is bugging me.

When I disconnect the power source from the laptop, I see the CPU downclocking to 0.8 GHz (I am using Intel XTU for monitoring). I understand this is done to extend the battery life.

However the thing is, when I connect the power back, the CPU shoots back to 3.3-3.5 GHz and then if I launch a game, it comes throttling back to the same 0.8 GHz.

Reboot fixes this. Naturally I am unwilling to reboot the laptop everytime I connect by power back so I need help fixing this problem.

I am running on BIOS 205.

unclewebb
12-19-2014, 11:07 PM
You can usually fix problems like this by using ThrottleStop. This can be a temporary solution until Asus fixes this with a bios update.

ThrottleStop 7.00 beta 3
https://www.sendspace.com/file/oquhg3

Check the Set Multiplier box, maximize that value and then click on the Turn On button and that should do it.

There is one register in the CPU that is used to request what multiplier the CPU should use. It is called the IA32_PERF_CTRL register. When this gets accidentally set to 8, the CPU will be stuck at just under 800 MHz. ThrottleStop adjusts this register so your CPU should be able to get back up to full speed. If this doesn't fix things, uncheck the BD PROCHOT box as well.

This program is safe when you are plugged in but do not use ThrottleStop to try and force your multiplier higher when you are running on battery power. Doing this can permanently damage or shorten the life of your battery if you do this while running a high load testing program like Prime95 or LinX.

hmscott
12-20-2014, 03:13 AM
I just got my G751JT-CH71 and this thing is bugging me.

When I disconnect the power source from the laptop, I see the CPU downclocking to 0.8 GHz (I am using Intel XTU for monitoring). I understand this is done to extend the battery life.

However the thing is, when I connect the power back, the CPU shoots back to 3.3-3.5 GHz and then if I launch a game, it comes throttling back to the same 0.8 GHz.

Reboot fixes this. Naturally I am unwilling to reboot the laptop everytime I connect by power back so I need help fixing this problem.

I am running on BIOS 205.

th3l34sh, try checking to see if the Power Plan got changed to Power Saving from Balanced or High Performance. Go into the Power Plan you have selected, I usually run Balanced and for Balanced I have the CPU Performance set to Min/Max 0%/100%. If you want to force 100% CPU, use the High Performance Plan and check CPU Min/Max is set to 100%/100%.

Asus Power4Gear used to cause this problem, it would put it's own plans in, switching at transition of power. I thought that Power4Gear wasn't included with the G751... the cure was to uninstall it or set back the Power Plan to Windows Balanced/High Performance from Power4Gear Power Saving Plan.

Please let us know what you find out :)

th3l34sh
12-28-2014, 05:36 PM
Hey sorry it took me this long to get back to you. I've been busy a bit and its been a nightmare trying to replicate the issue consistently. So here's what I've noticed so far:

Before starting this thread I had already checked that my High Performance Profile had CPU Performance set to 100%/100% while I left The Balanced Profile at stock settings because I want to get maximum possible time while on battery.

These are the two instances when I've noticed this happening (though it's not happening all the time):

1. I disconnect the power source and switch to Balanced Profile. I connect the power source back and set the Profile back to High Performance.
2. I switch the Profile to Balanced (while connected to power), put laptop to sleep, wake it up and set the Profile back to High Performance.

When I set the profile back to High Performance I can see the CPU clocks going to 3.5 GHz but as soon as launch a game or a stress test it comes back to 0.8 GHz.

Throttle stop as suggested by unclewebb seems to be forcing the CPU to go 3.5 GHz and it feels like it doesn't want to. Because as soon as I put some stress on the CPU the clocks start behaving erratically jumping around 0.8, 2.2, 2.8, 3.4 back and forth continuously. The performance in-game remains bad all the time during this behaviour.

Power4Gear is not installed.
Keeping the profile on High Performance causes no problems even if I disconnect the battery. It seems like the CPU is having troubles restoring its clocks after they have come down.

And as I mentioned above, reboot fixes this.

Any help is appreciated. Thank you :)

x7007
12-28-2014, 05:59 PM
everyone has this issue with 205 ? is this an issue with the firmware or just specific software bug ?

unclewebb
12-28-2014, 09:59 PM
th3l34sh - Can you post a screenshot of how you have ThrottleStop setup? For a simple stress test, try running 4 or 8 threads of the built in TS Bench test. Post a picture while this test is running.