Question Laptop CPU stuck at 0.4 GHz

Status
Not open for further replies.
Aug 4, 2021
8
0
10
0
I've got a problem with my Swift 3 laptop and I've spent a couple of hours searching for a solution, to no avail.

I have a Swift SF314-41 (N17W7) which has a Ryzen 3500U CPU.

The problem started yesterday without any obvious changes (no Windows updates, no damage, no new software, etc) and is now happening 100% consistently.

The problem is that shortly after a boot, or shortly after waking from sleep, the CPU gets stuck at 0.4 GHz, no matter what I am doing. This makes everything run excruciatingly slowly. Using Task Manager > Performance I can see that the total CPU usage is never higher than 19%, and it's often flat-lined at 19% in the graph.

It happens for both battery and AC power supply.

If I put it to sleep then wake it up, it will run at up to about 2.6 GHz for around 20-30 seconds, then it gets stuck back at 0.4 and doesn't go up again.

I've tried the battery reset via paperclip method but that had no effect on the problem.

I've checked the BIOS for any fan readings, but didn't find any. Oddly I can't hear a fan and I'm not sure I've ever heard a fan running in this laptop. Does it even have one? No software I've tried seems to show a fan speed, and fan speeds are all missing from tools like HWMonitor, Notebook FanControl, and a few others.

CPU temperature according to HWMonitor is around 60-80 degrees, but since the CPU can't work harder than 0.4 GHz it doesn't really seem to warm up any more than that, so I'm wondering if I don't hear the fan simply because it's not getting hot enough. The CPU temperature sensor seems to be operational and sane.

I've checked my Power settings in Windows and the maximum CPU performance is set to 100% for both battery and AC power. Minimum was set to 0% but I tried raising that and it didn't seem to make any difference.

I'm sure the AC power supply is working because I can see the laptop charging normally when it's connected.

I'm at a bit of a loss about this! What could it be?
 
Aug 4, 2021
8
0
10
0
Update: I've used an external fan and conduit to cool the CPU down to 30C, thinking maybe it's thermally throttling, perhaps due to a main fan failure, but even at 30C it's still throttling down to 0.4 GHz.
 
Sep 12, 2021
1
0
10
0
I had similar issue with my ASUS X512DA, CPU usage stuck at 19%.
  • NO HEAT ISSUE
  • NO BATTERY ISSUE
  • NO ADAPTER ISSUE
I just opened up laptop and remove the processor Heat Sink and cleaned up the old Thermal Paste and applied new one and everything works fine.
 
Aug 4, 2021
8
0
10
0
To follow up - I sent the laptop back to Acer who assessed it, found no fault, reinstalled Windows, sent it back, and it's working correctly now.

Given I reinstalled Windows (& Linux) several times myself before sending it to them, I suspect it either got a decent amount of percussive maintenance during freight, or they have some kind of special hardware reset tool they used to clear the fault.

Unfortunately if it happens again I am no further enlightened. @Bond007x I may resort to your method once it's out of warranty.
 
Jan 3, 2022
1
0
10
0
Same laptop, same CPU, same issue. Turns out, it was the fan. It got stuck on something, and stopped spinning, the laptop detected that and throttled the CPU.
Managed to get the foreign object out of my fan vents and everything went back to normal immediatly.

Would've been nice to have atleast a BIOS warning about it, but oh well!
 
Mar 14, 2022
3
1
10
0
Same laptop, same CPU, same issue. Turns out, it was the fan. It got stuck on something, and stopped spinning, the laptop detected that and throttled the CPU.
Managed to get the foreign object out of my fan vents and everything went back to normal immediatly.

Would've been nice to have atleast a BIOS warning about it, but oh well!
Did you hear it spinning loud or even spinning when it was working wrong? I have the same problem.
 
Reactions: miker305
Aug 4, 2021
8
0
10
0
Did you hear it spinning loud or even spinning when it was working wrong? I have the same problem.
This is a good point - in my original problem, I thought I could hear the fan, but I can't be sure. I did provide external air flow but that didn't help, but if the BIOS is using the fan tachometer rather than CPU temperature then that might explain the situation I saw. This might also explain why the fault disappeared when I returned it for service - perhaps whatever blocked it was dislodged in transit.

Annoyingly I wasn't able to find any software that could read the true fan speeds - this laptop uses some kind of proprietary fan controller.
 
Mar 14, 2022
3
1
10
0
This is a good point - in my original problem, I thought I could hear the fan, but I can't be sure. I did provide external air flow but that didn't help, but if the BIOS is using the fan tachometer rather than CPU temperature then that might explain the situation I saw. This might also explain why the fault disappeared when I returned it for service - perhaps whatever blocked it was dislodged in transit.

Annoyingly I wasn't able to find any software that could read the true fan speeds - this laptop uses some kind of proprietary fan controller.
Eh, i tried speedfan and other programs (today and few years ago), none of them shows fan speed. Very interesting thought about tachometer. So you think it could be fan fault (like bearing or something)? And the laptop thinks that if fan is working bad than it should slow cpu down?
https://forums.tomshardware.com/threads/cpu-sometimes-stuck-on-0-90-ggz-or-1-98-ggz-and-generally-works-slower.3754105/#post-22638456
Here's my thread if you're interested in reading my whole description of the problem.
 
Aug 4, 2021
8
0
10
0
Eh, i tried speedfan and other programs (today and few years ago), none of them shows fan speed. Very interesting thought about tachometer. So you think it could be fan fault (like bearing or something)? And the laptop thinks that if fan is working bad than it should slow cpu down?
https://forums.tomshardware.com/threads/cpu-sometimes-stuck-on-0-90-ggz-or-1-98-ggz-and-generally-works-slower.3754105/#post-22638456
Here's my thread if you're interested in reading my whole description of the problem.
Thanks for the thread link, I'll browse through it.

The repair report from the Acer service agent was completely unhelpful - it basically said they couldn't reproduce the fault, it worked fine out of the package I sent, and they did some diagnostic tests that all came back clear, and then just sent it back, working. It's worked fine since too.
 
Status
Not open for further replies.
Thread starter Similar threads Forum Replies Date
F Laptop Tech Support 0
WowFun77 Laptop Tech Support 0
Spiderman031 Laptop Tech Support 4
Orongo Laptop Tech Support 1
Y Laptop Tech Support 3
Justin.grewal Laptop Tech Support 1
M Laptop Tech Support 2
Arash.jahd Laptop Tech Support 0
John21903 Laptop Tech Support 2
J Laptop Tech Support 1
jasonkariuki98 Laptop Tech Support 1
C Laptop Tech Support 1
Plagu3Dr Laptop Tech Support 2
Unkn0wnUs3r Laptop Tech Support 0
buzzybabii_1 Laptop Tech Support 1
P Laptop Tech Support 0
SkiBaBopBaDopBop Laptop Tech Support 1
beejayel30 Laptop Tech Support 0
Komla Laptop Tech Support 4
T Laptop Tech Support 2

ASK THE COMMUNITY