Undervolting inefficient - i5 8250u

[cerqueiralf]

Hi all,

I have a Lenovo Ideapad 330, i5 8250u (base 1.6 ghz turbo 3.4 ghz), 8gb RAM and MX150.

I have tweaked a bit with throttlestop and managed a profile that allows the cpu to run at max clock (3.4) without thermal throttling or power throttling, which I thought were amazing results. Oh, that, during tests in throttlestop and cinebench (1638 score).

Problem is, when I turned to PES 2020, I noticed that the cpu was actually heating more than before, because the core was running all the time at max frequency.

When throttlestop is off, cpu ran at 60-70% at base clock (beggining at full, but then it was power throttled) and 65-70ºC. GPU about the same.

When I turn Throttlestop on, the cpu usage fell to about 50%, because the clock was at 3.4 the whole time, which wouldn't be an issue, if the temperature didn't go all the way to mid 80s.

I really like that I can get the turbo boost full time if needed and in a temperature that's not that high, but I wanted to let the clock fall, if it doesn't need to be at 100% (which the test without throttlestop showed).

Oh, I tried different values of speed shift EPP, but that just made the clock stay down, didn't fluctuate.

Any ideas? My goal is to give the CPU the possibility to run at full scale, but not if it's not necessary and lower the temperature, of course.

Here's the log file of a test with 16 threads and 1024M and the throttlestop settings. I didn't change iGPU Unslice (should I?) I can make other test and post other files if needed, just let me know

 

[unclewebb]

if the temperature didn't go all the way to mid 80s

What is wrong with that? Intel says that any temperature under 100°C is a safe operating temperature. That is why they have set the default thermal throttling temperature to 100°C for the vast majority of CPUs that they have built during the last 12 years. If this temperature was a problem, they would have lowered it years ago.

Stop trying to overthink your CPU. Trust Intel. The manufacturer of your laptop has lowered the thermal throttling temperature to 94°C. That is bad enough. No need to slow your CPU down more so it runs even cooler. I would go into the Options window and if it is not locked, I would set the PROCHOT Offset to 2 or 3. That will increase the thermal throttling temperature closer to the Intel recommended value of 100°C.

If you believe that you know more about CPU temperatures than Intel does, set up a profile for gaming which uses reduced turbo ratio limits. This will slow your CPU down and reduce the amount of heat it produces.

When undervolting the Intel GPU, you also need to undervolt the iGPU Unslice equally.

 

[cerqueiralf]

There's nothing wrong with the temp going up, I don't mind that it does if it gives me more performance, even if it reaches the thermal throttling. My issue is only that on the case of that particular game, it apparently didn't need to run at that frequency.

I was asking for a suggestion on what to do to make the undervolting a little more efficient.

Thanks for the info on the iGPU Unslice, will do.

I think I didn't explain myself right, let me try again.

While I don't have a problem with the temperature going up if it gives me more power, in the situation described, the notebook was running with higher temperature with throttlestop than without (because power and thermal limits were removed) but the performance didn't go up.

The CPU was running at a slightly lower percentage, but higher clock, leading to higher temperature, when the lower clock was enough for the activity at the moment (playing PES at 60 fps ).

What I'm looking for is a config in throttlestop that allows the CPU to crank it up if it needs to, but not run at full clock if it's not necessary.