Huge performance loss due to faulty cpu clockrate on Acer Aspire 3 A315-41-R2GU - how to fix it?

JohnnyK

Hello,

I discovered a weird behaviour which I have no solution for, yet. Under full load (CPU benchmark) the CPU is clocking the cores very differently after a few seconds of runtime.
One core runs at ~3.3 GHz, two others at ~ 2.3 GHz and one at ~1.5 GHz. This results in an overall performance loss of >20%. Because one core is running at ~3.3 GHz, the cpu runs at higher voltage and gets hotter which results in the thermal throttleing of the other cores (I suppose).
I've tested this with Cinebench R15, Prime95 and AIDA64 stability test - same outcome (I've linked the images below). Which drives me nuts is that this wasn't always the case. I've seen it running stable at 2.9-3.1 GHz on all cores at a lower voltage (75°C) on all tests for a longer period of time and it never dropped into this weird behaviour. I got a maximum cinebench R15 score of 690 back then, now its only 510 - always.

Test-conditions: 20°C room temperature, 100% charged, mouse attached, WLAN off, networkcable attached, kill-a-watt-meter applied.
What I already tried:
- changing windows 10 powerplans (balanced, high, ultra),  on desktop ryzen there seems to be a additional ryzen powerplan.
- flashed between BIOS 1.08 and BIOS 1.09 multiple times (happens with both of them).
- changed the thermalpaste on the CPU (Noctua NT-H1) multiple times, checked the contact pressure and thermalpaste distribution.
- installed the newest GPU driver manually.

- rebooting several times.

Anyone with a similar experience?

Thanks for your help in advance.

ilhamzap

Yeah, nice price you got for that used device, very worth it IMO. It seems you really don't need a laptop or portable PC?

Well, they finished it last Saturday.
And no changes they said, they already checked some new product, same problem, and a new motherboard for my laptop also the same problem. But the first try could get near 600 or maybe 600+. Normal they said.
Well, it's maybe because processor couldn't utilize it's maxed potential. I checked power usage in various software (HWMonitor, HWInfo, AIDA64, etc) a few seconds CineBench running, could get a little bit more than 13W, the rest around 11W (maybe 10-12W, forgot it and bored to retest it again), it's because of 75°C temp limitation probably.
They decide to use my old motherboard. And they found that bad hard disk condition causes a slight lag in my laptop, then they had to replace it. Much better but still need to deal with this processor problem.

For me, this Acer laptop still a good deal compared to Asus or HP, easy upgrade and 2 slots of RAM ofc none soldered, price, already 8GB dual-channel, etc.
Ryzen 2? 2500U already the second generation of Ryzen, and for the mobile/ laptop without taste any first generation and none built for a laptop.
Waiting for 3700U I guess, Ryzen 7 still, the same spec like 2700U but with higher IPC, same TDP, and other specs = better performance of course,

In 2 weeks, I'll try to repaste with one of the best paste, Thermal Grizzly Kryonaut, this week shipped and arrived, next week to repaste it to Acer center ofc, no warranty void. And see if this solution works also will try Opolar vacuum cooler (or similar product) rather than cooling pad (almost no use, except to give some space underneath laptop for circulation) later.

Yea, someone said Acer use bad thermal paste according to an old thread.