[SOLVED] Undervolting - modern solutions?

Kalrish · 2013-06-21 18:19:01

Hello everyone!

My CPU is always at very high temperature, so I looked for solutions. Apart from disabling things (which I had already done) and changing some configurations to reduce performance (something I don't want, since this computer is not that good and, if I want to do useful things, I need performance), I found a very interesting one: undervolting. A deep reading finally convinced me: performance would not be hurt, and I would be able to strip off those surplus volts that are causing overheat.

The only solution I found, even on the wiki, was PHC. I downloaded the tar from the AUR and started compiling, but was disappointed with some things:

Errors during build. I had to edit the source in order to make it compilable.
It seemed that even its latest release is designed for the 2.6 kernel.

So, I'm looking for a more recent patch (or, even better, a mainline kernel interface) to achieve this. Unfortunately, my programming skills are not as good as I'd like, so I'm unable to go hardcore and edit acpi-cpufreq by myself. Trying to find something in sysfs has failed; searching through the web always drives me to linux-phc.org.

Thanks in advance! Best regards,
Kalrish

EDIT: Excuse me, I forgot to mark as solved.

Last edited by Kalrish (2013-06-25 16:09:05)

steinchen · 2013-06-22 19:16:35

Hello Kalrish.

You could try setting a lower cpu-voltage via your BIOS-settings, or just renewing the thermal grease on the cpu-heatsink.

Regards, steinchen

ewaller · 2013-06-22 20:02:33

steinchen wrote:

Hello Kalrish.
..., or just renewing the thermal grease on the cpu-heatsink.

Except, many modern systems use Phase Change Metal Alloy (PCMA) rather than a silicon based grease. PCMA has much lower thermal resistance than does the best thermal grease and does not dry out. Make sure you don't make things worse.

steinchen · 2013-06-22 21:17:08

@ewaller

English insn't my native language, so i had a look at some of the products i meant to suggest and the english translation only said "thermal grease".
I'm sorry if this might've caused some confusion or misunderstanding.

steinchen

Kalrish · 2013-06-22 21:32:38

steinchen wrote:

You could try setting a lower cpu-voltage via your BIOS-settings, or just renewing the thermal grease on the cpu-heatsink.

Thanks for your answer. Unfortunately, my BIOS is anything but useful (really, it's like if you took a piece of shit from the ground and put it into a motherboard), and does not offer any voltage-related options. And, well, this is a laptop, so accessing the processor would be tricky. (I know all laptops suffer from overheating issues, but, well, I'd like to keep my only computer from burning.)

cfr · 2013-06-22 22:30:07

Just as a sanity check: what sort of temperatures are you seeing?

Kalrish · 2013-06-22 22:42:39

cfr wrote:

Just as a sanity check: what sort of temperatures are you seeing?

Around 100 celsius right now, compiling GCC. I have two cores and the BFS, so I just made 'make -j2'.

When surfing the web, about 60 degrees (Chromium; from official repos). Viewing videos in high definition or in fullscreen mode rises CPU temperature to 80 degrees (I can not offload video processing to the GPU). And, finally, without doing anything, it is near 50.

(I must mention I live in the south of Spain; here the summer is incredibly hot, so ambient temperature also contributes overheating. I can't measure it, though.)

mich41 · 2013-06-23 14:16:27

Dunno about Intel, but there's K10ctl for recent AMD CPUs. Should be quite reliable since it manipulates CPU registers directly without screwing with ACPI.

However, it's unlikely that you will be able to get much improvement. My CPU throws MCEs after even a tiny voltage reduction, without any significant difference in temperature.

I'm afraid that you will have to get your hands dirty and take the sucker apart to clean heatsinks from dust, as this is likely the root cause of overheating.

Kalrish · 2013-06-23 18:11:24

@mich41

My processor is a K8. I also got confused about that: www.tomshardware.com. I have tried it anyway, and it fails as it should:

Warning: No AMD Family 10h processor

Thank you all, in any case. I guess you're right and that I'll have to "get my hands dirty".

As to marking as solved, I'm not sure. May this post be of any usefulness in the future, to anyone searching out there?

cfr · 2013-06-23 23:27:44

Have you tried using a "cool pad"? They sell them for laptops and basically, they raise the laptop at a slight angle. This means that air circulates underneath the laptop a lot better then when it is flat on a desk. It also makes it more comfortable to type which is actually the reason I originally got one. They come in portable versions which just raise it a bit by a fixed amount and less-portable versions which can raise it more and vary the height. At least, that is what mine are like.

Though if the fan is full of dust, I don't think anything much short of cleaning it is going to make a lot of difference.

straykat · 2013-06-24 07:21:38

Kalrish,
It may be worthwhile isolating the problem & fixing that before trying undervolting as undervolting is not going to solve your problem.

Have you googled your problem to see if this a common issue with your laptop?

Is your fan still working?

Have tried removing access panels & blowing your laptop out with low pressure compressed air? It could be as simple as your heat sink & air channels are clogged.

It gets warm here in Queensland, Australia so I find blowing out my laptop & desktop each spring a must.

indianahorst · 2013-06-24 10:53:10

Kalrish wrote:

@mich41
My processor is a K8. I also got confused about that: www.tomshardware.com. I have tried it anyway, and it fails as it should:
Warning: No AMD Family 10h processor
Thank you all, in any case. I guess you're right and that I'll have to "get my hands dirty".
As to marking as solved, I'm not sure. May this post be of any usefulness in the future, to anyone searching out there?

With a K8 CPU you can use cpupowerd (https://aur.archlinux.org/packages/cpupowerd/). You have to use the PKGBUILD which I posted as the top comment, because the PKGBUILD in the AUR is incorrect. Once you have cpupowerd installed, just read the README (/usr/share/cpupowerd/README). It's really well documented.

ANOKNUSA · 2013-06-24 12:52:21

Kalrish, which GPU driver do you use? The open-source ATI/AMD drivers are crap with integrated graphics; on my previous machine, installing the proprietary drivers usually brought the temp down to a reasonable (or at least manageable) level.

Kalrish · 2013-06-25 15:14:57

I'm sorry for not posting before.

cfr wrote:

Have you tried using a "cool pad"?

I already had one. I think it does not make a very big difference, but that may depend on the design of each laptop.

cfr wrote:

It also makes it more comfortable to type which is actually the reason I originally got one.

Totally agree with you.

straykat wrote:

Have you googled your problem to see if this a common issue with your laptop?

Yes, and it's indeed common. I found a post a while ago that explained how to make some holes at the bottom, thus providing fresh air to the board. Can't find the link, however.

straykat wrote:

Is your fan still working?

Yes, it is.

straykat wrote:

Have tried removing access panels & blowing your laptop out with low pressure compressed air? It could be as simple as your heat sink & air channels are clogged.

Well, I followed part of this tutorial years ago, and have been cleaning the fan with the vacuum since then periodically. I tried to follow it to the end, but I couldn't extract the top cover. As I've never built my own computer, nor completely dissasembled a desktop one, I felt a bit scared about damaging it and assembled it again.

ANOKNUSA wrote:

Kalrish, which GPU driver do you use?

The open source drivers. Due to my philosophy, to the problems installing the propietary driver would bring to me (downgrading X, and maybe more things) and to (I'm not sure, though) AMD discontinuing development of their drivers for my card (Radeon HD 3200), I won't install the propietary ones.

I've partially solved the problem. It still gets warm, but that's something most likely related to the inside of the laptop, so I guess I will stick with it. Thanks a lot; you have been of much help.

Clean the computer. Esential.
Enable power management in the kernel side. It's something I completely forgot about; in the kernel command line, I have radeon.pm=0, which disables power management of the card. Removing it has made a huge difference and has let me change power profiles of my card, as I explain below. I doubt any of you have played with those options, so I guess this "solution" will not be useful to much people. After enabling power management, you have to follow the instructions here and set profile as power_method, and low as power_profile. Well, "low" or whatever you wanted.

Thanks to the above, the temperature is now around 50 ºC (Chromium, Xfce). It's about 10 ºC less.

What can I say? Thanks a lot, really. I'm very glad it is, at least, working.

Best regards,
Kalrish

Arch Linux

#1 2013-06-21 18:19:01

[SOLVED] Undervolting - modern solutions?

#2 2013-06-22 19:16:35

Re: [SOLVED] Undervolting - modern solutions?

#3 2013-06-22 20:02:33

Re: [SOLVED] Undervolting - modern solutions?

#4 2013-06-22 21:17:08

Re: [SOLVED] Undervolting - modern solutions?

#5 2013-06-22 21:32:38

Re: [SOLVED] Undervolting - modern solutions?

#6 2013-06-22 22:30:07

Re: [SOLVED] Undervolting - modern solutions?

#7 2013-06-22 22:42:39

Re: [SOLVED] Undervolting - modern solutions?

#8 2013-06-23 14:16:27

Re: [SOLVED] Undervolting - modern solutions?

#9 2013-06-23 18:11:24

Re: [SOLVED] Undervolting - modern solutions?

#10 2013-06-23 23:27:44

Re: [SOLVED] Undervolting - modern solutions?

#11 2013-06-24 07:21:38

Re: [SOLVED] Undervolting - modern solutions?

#12 2013-06-24 10:53:10

Re: [SOLVED] Undervolting - modern solutions?

#13 2013-06-24 12:52:21

Re: [SOLVED] Undervolting - modern solutions?

#14 2013-06-25 15:14:57

Re: [SOLVED] Undervolting - modern solutions?

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