Attention N200 Owners, I found a fix for the fan [ Edited ]

[konfuzd]

In an attempt to improve battery life, I made an important discovery. Apparently lenovo is using the desktop CPU P States instead of the mobile ones. With my T7200 running at 2GHz, this means it's using 1.35V instead of the 1.225V it's supposed to be. This mistake on lenovo's part means increased heat output and a fan that has no idea how fast to run. Here's how to fix it:

1. Download and Install RightMark CPU Clock Utility. http://cpu.rightmark.org/download.shtml

2. Open the utility and select "Advanced CPU Settings" in the pane on the left side.

3. Towards the bottom under "Intel Core 2 Family Advanced Features", change the "CPU type selection" setting from desktop to mobile.

In  order to make this change stick, you have to make the RightMark CPU Clock Utility run at startup.

1. Click on settings in the pane on the left side.

2. Check the box next to "Run at Startup"

3. Select "via Startup Folder" in the pull down box.

4. You may also want to check the "Start Minimized to Tray" box above, or the main window will open every time you start the computer.

Untill lenovo does something about this problem, this is all you can do. However, you will see an improvement in battery life and a reduction in noise, along with a fan that does not have ADD.

Moderator Note; converted to clickable link

Message Edited by andyP on 04-15-2008 09:23 AM

[iamdh]

Changing default voltage of CPU fan seems a little risky business.
Let's see what mods say about this.
Till then I won't think of trying it.

[oNeill]

@iamdh

He doesn´t change the voltage of the CPU fan which could indeed be a little risky. He changes the voltage of the CPU which is according to CPU-Z by default (http://www.cpuid.com/cpuz.php) a little higher than the default voltage of the CPU.

I also noticed this before and did exactly the same with my 3000 N200. The difference is just that my N200 has a T5250 CPU but as it seems the same overvoltage problem. With his workaround the heat and powerconsumption is especially under high load reduced, resulting in a higher runtime.

On the other hand this has hardly any effect on the fan spining up an down when the CPU is idle.

Sorry, small addition:

I used another way to get the "right" voltages for my CPU. When I open RMClock my CPU already is marked as an mobile CPU, so this is not the problem in my case. But you can also change voltages for the different Pstates in RMClock manually. And this is what I did to get the default voltages for my CPU. Interested ones can find the necessary information here http://forum.notebookreview.com/showthread.php?p=2637648 (They describe how to undervolt a CPU but as a start it is just enough to supply the CPU with the default voltage instead of the "higher than above" voltage supplied by for example my 3000 N200)

Just for information: The default Voltage of my T5250 CPU is 0.95 Volt at idle and 1.25 at load. According to CPU-Z my CPU gets 1.063 Volt at idle and 1.363 Volt at load. 

Message Edited by oNeill on 04-15-2008 05:35 PM

[konfuzd]

oNeill, have you submitted a bug report on this issue yet? I'm going to tomorrow and it would look better if I'm not the only one who has the problem. Also, what's the model number for your n200?

EDIT: iamdh, this isn't undervolting. It's changing the voltages to what they should be. When lenovo made the bios, power management driver, or whatever actually controlls this, they mistakenly refrenced the desktop p states, or clockspeeds and voltages, instead of the laptop ones. These p states are created by intel and are what the CPU is certified to be capable of. My only changing the switch from desktop to mobile, you are effectively correcting the mistake.


Message Edited by konfuzd on 04-15-2008 08:03 PM

[wowow]

hi

i have the same problem with n100 (FPG ) duocore 1.8

http://forums.lenovo.com/lnv/board/message?board.id=N_Series_Lenovo_3000&thread.id=1803

its not n200 problem . its also  n100 problem
i hope someone report the issue to lenovo support team
the problem is big. its not small it all
its good if you change the headline for you message from (Attention N200 Owners, I found a fix for the fan) to (Attention Nxxx Owners, I found a fix for the fan)

Message Edited by wowow on 04-15-2008 11:11 PM

Message Edited by wowow on 04-15-2008 11:14 PM

[oNeill]

konfuzd, did the switch from desktop to mobile cpu really help? Because as I said before according to RMClock with my N200 BEG the CPU is recognized as a mobile CPU by default.

But on the other hand I have the problem that my CPU gets to much voltage even it is detected as mobile. It would probably a good idea if you download CPU-Z (http://www.cpuid.com/cpuz.php) and check the voltages supplied to your CPU just to be sure.

[konfuzd]

It made a huge difference at load. Instead of the fan rapidly switching between loud and louder with temps up around 70C, the fan is audible, but not by much and the temps are only 60C max.

[oNeill]

konfuzd: Ok, the question is if the CPU now gets really the right Voltage.

I think we have two different problems here. Your problem is that your CPU wasn´t recognized as a mobile CPU and so it gets more voltage. You solved this by switching to mobile in RMClock.

My problem is (also) that my CPU gets to much voltage but the reason for this is in my case that the voltage regulators supply to many volts to my cpu and not like in your case that the voltage regulators get the wrong voltage identification from the CPU/Mainboard/BIOS whatever. The regulators of my N200 get the identification signals for 1.25 V but supply 1.363 V...

The question for me is if your (konfuzd) CPU gets really the right voltage now or if you have in addition to the solved mobile-desktop switch problem also my overvoltage problem. So it would be interessting to know what CPU-Z reads from your CPU Voltage sensor. 

[konfuzd]

When using a version of CPU-Z that recognizes Super LFM (1.40.5 was the last one), it agrees with the voltages being set in RM Clock. Here's the P-State table from RM Clock on mobile. I also realized I said the wrong CPU. It's a T7300 (10x200MHz), not a T7200 (12x166MHz)

Super LFM 8x100 --- 0.8500V
LFM            6x200 --- 0.9375V
                   7x200 --- 1.0125V
                   8x200 --- 1.0750V
                   9x200 --- 1.1500V
                 10x200 --- 1.2250V
IDA           11x200 --- 1.3000V

This matches the range specified here for my CPU stepping.

http://www.cpu-world.com/sspec/SL/SLA45.html

Here's the P-States it defaults to:

Super LFM 8x100 --- 0.9625V
LFM           6x200 --- 1.0500V
                  7x200 --- 1.1250V
                  8x200 --- 1.1875V
                  9x200 --- 1.2625V
                10x200 --- 1.3375V
IDA          11x200 --- 1.4125V

Well above the specified voltage range. The 8x100, 6x200, 8x200, and 10x200 P-States I observed in CPU-Z before even messing with RM Clock.

[oNeill]

After some thinking and research I come to the conclusion that my problem is non existent.

I think that CPU-Z just reports the wrong voltage or in other words is not capable to read out the right voltages. It would be very strange that both idle (1.063 - 0.95 = 0.113) and load (1.363 - 1.25 = 0.113) voltages have the same offset (0.113) from the default as voltage normaly fluctuates a bit. There might be no real sensor chip like on normal motherboards as no other programm can read voltages on the N200. Probably CPU-Z also just reads the VID signals and does this obviously the wrong way.

Since I don´t have this problem (as mentioned before my N200 shows the CPU directly as mobile in the advanced features in RMClock) this bug is probably related to the other CPU-Class (T7xxx - T5xxx) or to an older BIOS version.