E6400 overheating throttling

Hello there,

I'm so glad I finally found out what my problem is with that laptop... it has been running fine until the hot temperatures of summer here in France.

For a long time I thought it was related to some software I was running but obviously I was wrong.

I already called Dell about this and I got my motherboard changed without any improvement. What I don't understand is that the problem occurs to some users and some others are safe, so what's the difference between their laptops? I have the Intel chipset which has been replaced like almost all the hardware except RAM, CPU and FAN...

So our best hope is to wait for a new BIOS which would set the throttle threshold to higher temperatures? Did anyone success in getting the full laptop replaced from Dell? I just can't work with it, I must reboot like twice a day at work...

 

I think the reason why a lot of people haven't noticed the problem is because it doesn't happen very often if you don't run graphics applications like Google Earth for a while in a room with temperature above 25C. I don't think my laptop has ever throttled down except for when I pushed it hard to try to reproduce the problem. And also it happens more easy if the have the laptop docked with the lid closed. And a lot of people doesn't have a docking station. So it depends a lot on how you use the laptop.

Most people use their Latitude E6400/E6500 for lightweight office tasks (Office, e-mail etc) in air conditioned offices with temperatures below 25C and they are not very likely to get throttling problems.

I am more annoyed by the fan problem. Now in summer time when my room temperature is often 26C-28C the fan starts running at full speed quite often. Watching a youtube clip or browsing a web page with flash animation is often enough to cause the chipset to reach 50C which in turn triggers the very noisy full speed fan mode. That is not acceptable for a an expensive business class laptop.

Örjan

 

I forgot to mention that most of the time the throttle occurs while my laptop is idling! It can happen just randomly when I have nothing else opened than 4 terminals under GNU/Linux, no graphic software involved (no screensaver, no flash player in a Firefox tab, etc.) and CPU at 50-52°C.

I asked forums and some users get an idle CPU temperature of ~35°C whereas I idle at 50°C even if the CPU is scaled to 800 MHz, this is one of the things I don't understand... why such differences?

 

Are you sure about the CPU temperature? With an Intel Core CPU you can get different readings for CPU temperature from different sensors. When people say they have a CPU temperature of ~35C they probably mean the CORE temperature of a single CPU core. It is normal for that temperature to be ~35C. My CPU cores are both ~35C now at idle load with 26C room temperature as reported by I8kfanGUI and CPUID Hardware Monitor. Depending on what tool you use for reading the CPU sensors it is normal to get a 5-10C higher reading with some tools.

The CPU temperature doesn't seem to cause much problem on E6400. I can have CPU core temperatures of 60-70C (CPU "non-core" temp ~75C) on my E6400 with the fan still running in slow 3000 RPM mode and no throttling active as long as the chipset temperature is low.

 

I thought this whole throttling thing can only be triggered by graphics intensive apps but how about this one: I left the laptop with Vista's bubble screensaver (for my daughter to watch) running for a few minutes and lo and behold, the CPU got throttled. I did not think a simple screensaver is capable of doing that

 

Is it a windows-level throttle or firmware? Try setting screen saver>power settings> "performance mode". This should disable any throttling by windows. If it still happens than we know it is the bios!

 

I have this problem also, and it is definitely the BIOS (system firmware) throttling the machine. If you look in the Event Log, you will see that it states that, "The speed of processor x is being limited by system firmware. The processor has been in this reduced performance state since n seconds since the last report," where x and n are dependent upon your circumstance and system. Also, I have tried performance mode before, and the BIOS is throttling the machine. This problem can be reproduced reliably if you boot up Half-Life 2 and play it for 10 or 20 minutes. You will start getting increasingly low framerates since the will greatly throttle the CPU.

 

Ok you guys need to think here
A room temperature of near 30C is insane. I turned off the A/C of my room and closed the door to ave a hot room, and even my DESKTOP computer act like if I am playing a game. Meaning that the fans goes at high speed.

I think I know the problem. The casing is in metal. See your room is soo hot (even table), that it actually heats up the laptop instead of cooling off.
Another thing, The Intel GPU is included in the motherboard northbridge. If the northbridge throttles than the hole computer goes down with it, as this is where all the important communication between components happens. So, my guess is that heats-up too much, and already the fan kicks in for nothing, when it warms up. Running GPU intensive app doesn't help that GPU.
And, yes even the bubble screen saver is hard for such GPU, especially that the drivers was most probably not optimized for the screen saver (as Intel GPU driver is a per application basis, and not universal like Nvidia, which provides some up and down sides).

I am trying to test this for you guys. I closed teh A/C, light maximum light in the room, closed the door of my room. Now the room is warm. I don't have anything to measure the room temps, what are your system temperature for me to try to simulator the problem on my side?

 

Correct, but I don't think it's something Dell can do, it's more like Intel on the GPU, CPU and northbridge.

OK, before I start, my temp in my warm room is: GPU is currently at 57C, chipset 58C, fan 3000RPM.
Wow... I can play several hours on a hot room HalfLife 2, Team Forterest 2, and the laptop doesn't slow down one bit. I am also trying Google Earth spinning the globe continuously, and the GPU is acting like it's nothing. (I am still in my warm room).

I truly thing it is because the Intel 4500X GPU is not separate like the older Intel GPU but in the northbrdige.

Of course, all I am saying (and on the previous) post are simple unproven theories.

 

I still haven't had the problem. My laptop is about a week old, I even downloaded the Call of Duty 4 Trial to test how well the laptop would perform, and I played through the whole trial (roughly 20 minutes) and didn't notice any throttling. I wasn't watching the temps, but I did not notice the system slow down at all, it actually played the game quite well.