Thinkpads Forum

Hi,

I am very sensitive to noise, especially when I need full attention while working on something important, such as writing a paper. My Macbook was making this constant buzzing noise, which was very irritating to me. I posted a question in the General Questions section, seeking advice on obtaining a quiet computer. SSD_Thinkpad suggested, among other things, that I should try T400 since it is a very quiet machine. And I was very thrilled to know that.

However, today I finally figured out what the noise from my Macbook is about, after some research on the internet. Apparently, this is due to the Intel Core Duo and Core 2 Duo:

Almost every Intel Core Duo and Core 2 Duo I've ever seen/used makes some noise at/near the CPU--esp. the Macbooks and Macbook Pros.

I believe it's normal, and I'll tell you why I believe this--the issue is only happening when the CPU is idle (not under any load). However, when you put a load on it, the sound goes away. This is most likely due to power fluctuation, although specifically I cannot tell you how/why--my experience w/ electrical engineering is somewhat limited...(history major). hehe. Maybe some electrical engineers would like to chime in?

Above quote from: http://www.notebookforums.com/thread191970.html

I tried the advice given by other people on the internet who have reported this problem. The advice generally is to use some application so that CPU will not become idle, since it produces the irritating noise only when it is idle. One person advised opening the Mac application Photo Booth. I followed that advice and THE NOISE IMMEDIATELY STOPPED.

Now here is why I am providing all this background: I still want to purchase a T400 (or any other high quality Thinkpad laptop). But, it seems that as long as the machine uses Intel Core Duo and Core 2 Duo, then there would likely be noise from the CPU when it is idle.

Are there any Thinkpad laptop that does not use Intel Core Duo and Core 2 Duo?

What about those who are using T400 (which does use Core 2 Duo, I believe)? Is it producing a buzzing irritating noise when CPU is relatively in idle state?

Any advice would be appreciated.

Thanks!

When using the cpu all the time for not using the most energy saving cpu c4 state, it is bad for your battery life. There are better ways to fight the cpu noise There are two ways to shutdown the cpu whining (sound that comes when changing from energy saving cpu c3 state to more energy saving cpu c4 state) with the free program rmclock:

rmclock > Advanced CPU settings > Chipset > disable both "Enable Popup Mode" and "Enable Popdown Mode".

(You can completely disable cpu c4 state with: rmclock > Advanced CPU settings > Chipset > enable "Disable C4 Mode")

T400 here. I have the power state set to "Always On", then I tweak it from there. I do that so the CPU doesn't step at all. I want all the power there is, all the time. I very rarely just use it on battery, because I'm all about speed. Since your all about quiet, maybe you need to do the same.

Yup, it's the C4 state that causes that whine. The sound actually comes from the motherboard. You can encounter this regardless of the cpu.

I think I'm experiencing this on my T400, seems to be effected by starting up the computer, resuming, putting the AC adaptor in and out.

It appears to be coming from the top left corner near the Thinkvantage button, which is where the CPU is. It sounds like a capacitor discharging or something. I'd describe it more as a squeak. If this is indeed the case, is the noise symptomatic of damage or impending damage, or is it perfectly safe? Thank-you.