8750H idle high clock / cpu usage

[powajoj]

Hello guys,

I just bought a new laptop Lenovo Y740 15inch and there is a small problem with the CPU on idle. Everything is ok on battery but when plugged in CPU is at 3.9-4.0Ghz all the time. I have checked forums and internet but I am not able to find out what is causing this.

My battery plan is on balanced. CPU min when plugged in is 5% and max at 100%. When i drop the max % it will drop normally but it defaults to max.

In task manager avg cpu usage is around 2-15% with browser and some other apps open but nothing demanding. Those should not bump up cpu speed to those numbers. Battery slider is in the middle, and plan balanced. In ThrottleStop C0% is floating between 6 to 10. I have no idea how to fix this and what could be causing this, there is no power hog application running. Currently I have open only ThrottleStop, MSI afterburner graph, Chrome and Task Manager but even if I close those programs I can tell its on the high clock as the fans are going.

Any advice would be appreciated. Thank you guys.

 

[Bill_Bright]

What does the manual say?

Frankly, I would be more the concerned if this happened the other way around - that is, when on battery, the CPU speed jumped up.

Did you change any settings in the BIOS Setup Menu?

My battery plan is on balanced.

But this has nothing to do with the battery. You said this only happens when plugged in. Most (if not all) notebooks use 2 different sets of "Power options". One for when on battery to conserve battery power and extend battery run time, and the other when running off the charger when conserving battery power is not a concern.

 

[powajoj]

I had a look at the bios option but there isnt much I can change. It's modified by lenovo so you cant fiddle too much with it. No options for CPU or power there. Just boot, disable integrated GPU, usb etc.

The power plan should be also used when plugged in. There are sections for when plugged in so it should downclock when plugged in and not using resources. It's just going full blast. In the lenovo vantage software there is no option for plugged in performance or anything similar. There is no need for the CPU to go 24/7 on 4ghz when idling just because it's plugged in. I think that is wrong so I'm looking for some advice. I dont care about lifespan reduction or so, it's just noise and hear that's bothering me because its 'idling' on 60 celsius so the fans are always enabled.

 

[Bill_Bright]

The power plan should be also used when plugged in.

On PCs, yes. But with notebooks, there are two - one for on battery and one for on charger. On my Toshiba, they are under "Eco" settings and they also cut back on screen brightness, keyboard LEDs, and other power eating features.

There are sections for when plugged in so it should downclock when plugged in and not using resources. It's just going full blast.

Just you just walk away for awhile to see if it eventually settles down? You said this is a new notebook. Depending on how long it sat on the shelves, it could be months behind in updates. Other "housekeeping" chores could be behind too - such as indexing, defragging, security scans, etc.

There is no need for the CPU to go 24/7 on 4ghz when idling just because it's plugged in.

I agree. But why would it stay on for 24/7 if idle. Are now saying it doesn't go to sleep?

To be sure, if there is a fault here, don't do anything to void your warranty.

 

[unclewebb]

A reasonably fast 4 core CPU can run Windows 10, Avast antivirus and ThrottleStop while only needing to average 0.2% to 0.3% of its time in the C0 state.

there is no power hog application running

There IS a power hog application running.

In ThrottleStop C0% is floating between 6 to 10.

An 8750H has 6 cores and 12 threads. Average C0% at 8% X 12 threads = 96%.

Translation: You have the equivalent of a task running on your computer that is fully loading one core. A modern Intel CPU will not slow down if it is loaded like this. When a CPU has something to do, it is designed to run at full speed. Open up your Task Manager, go to the Details tab, click on the CPU heading and organize your tasks by CPU usage. Find out what background tasks are running on your computer and decide how badly you need them. Some software is very inefficient. Get rid of everything one by one until you isolate the problem. The C state and C0% data in ThrottleStop can help you track down the bad stuff. An idle CPU should show the cores spending 99% of the time in the low power C7 state.

Most laptops running Windows 10 with 8th Gen CPUs use Speed Shift to control the CPU speed. If you are using Windows to control your CPU speed, make sure Speed Shift EPP is not checked in ThrottleStop. Open up the FIVR window. What is being reported for Speed Shift EPP in the monitoring table at the top right?

 

[powajoj]

Speed shift EPP in FIVR top right is 84 voltage. In the task manager, ordering by CPU, first is system idle at 96-98 and then everything at 00, occasionaly some process pops at 01.

 

[unclewebb]

An EPP setting of 84 should allow your CPU to slow down if it has nothing to do. Close MSI Afterburner, Chrome and the Task Manager. Post a screenshot with only ThrottleStop open on the desktop. You can hold down the ALT key while pushing the PRINT SCREEN button on your keyboard to take a snapshot of only ThrottleStop. After that you can paste the screenshot into any paint program and attach it here or upload it to imgur.com

Edit - Everyone likes to see a slow CPU when idle. My question is why? If the C states are enabled, idle cores will be in C7 running at 0 MHz and 0 Volts. In this situation, whether software reports the CPU as fast or slow does not make any significant difference. Check out this comparison. When idle, the reported power consumption and the core temperatures are pretty much identical even when the CPU is running 3 times as fast.

The left side was with an EPP setting of 84 and the right side used an EPP setting of 0 to obtain maximum speed.

 

[powajoj]

This is with everything closed