laptop Laptop CPU keeps underclocking itself.

[BlueMurLoc]

Hey guys!

 

About two months ago i bought a new Lenovo Legion Y720 laptop.

At first i was really happy with it, as it has a a nice screen, nice keyboard and trackpad and a nice sound system.

 

But as i started playing more games I realised that the CPU, even under 100% load would underclock itself.

The i7 7700hq is supposed to run at at least 2.8Ghz, and even turbo-boost.

For a split second as I start a game it will go up to 3.7-3.8 Ghz and then go down to 2.69 Ghz (constant) for the rest of the game.

The laptop is not overheating, as i monitored it staying at a toasty but constant 75-80 C. (the fans don't even ramp up to 100%)

Even with the fans set to run at 100% constantly, the temp goes down to about 70 C, but it still remains at 2.69.

 

I have tried everything, from cleaning the heatsink (it was not even dusty), to bios updates (up to the latest version as of 21/02/2018).

Do you guys have any ideas what else to try? Or is it normal? Most CPU intensive games have a big drop in fps (CSGO on 720p on very low ~180FPS), where other games are fine (PUBG on 1080p, low ~70, OW on 1080p epic ~ 120)

[Jurrunio]

hitting power draw limit probably. You can try undervolt the CPU and reduce the power draw, which then allows the CPU to run with higher clocks under the same power limit.

[BlueMurLoc]

I tried that as well, undervolted it to -0.020, but still did the thing. Should i go even lower?

[whoisit1118]

The 7700hq can undervolt around 150mV in most cases, although you would want to run a stress test to make sure. That should allow the CPU to max its maximum boost.

[BlueMurLoc]

Will try this and post the results. Cheers everybody! <3

[BlueMurLoc]

Reporting back!

 

The lowest i could get the processor to run stable was -0.135. Anything more and it would crash under any load.

But the problem still persists...

 

Here is a screeshot of the underclocking:

 

Any other ideas?

[Ahmad7sh]

Same problem with legion y720, do you find any solution?

[BlueMurLoc]

On 6/11/2018 at 6:49 PM, Ahmad7sh said:

Same problem with legion y720, do you find any solution?

Nope. I did everything i could. I sent it back for warranty, came back the exact same, with "no issue found", i changed the thermal paste on both the CPU and GPU with Noctua stuff and undervolted the crap out of it. Nothing helps. Whenever the laptop is under sustained load, even if it sits at about 60 - 70 C, it will drop down to 2.69 Ghz for no reason.

My only thought is that it is programmed to behave like this, which is really shitty, especially when the cooling solution is more than adeqate...

 

I'm still open for other people's solutions...

 

EDIT: I have found that you can increase the FPS of your games quite a lot by plugging in an external display. In CS GO i went from ~180 to ~240!!!! Again, i think this has something to do with the Intel HD Graphics chip and/or drivers.