ThinkWiki - User contributions [en]

Category:SL300

2009-09-14T15:11:37Z

Fthieme: /* Issues */

Category:SL300

2009-09-14T15:09:11Z

Fthieme: Pointing to SL Series, because of most issues are non-issues nowadays

Template:SL300

2009-01-18T22:34:10Z

Fthieme: â†Created page with 'SL300Category:SL300'

[[:Category:SL300|SL300]][[Category:SL300]]

Intel Core 2 Duo (Merom)

2009-01-18T22:29:12Z

Fthieme: /* Standard Voltage */

{| width="100%"
|style="vertical-align:top;padding-right:20px;width:10px;white-space:nowrap;" | __TOC__
|style="vertical-align:top" |
<div style="margin: 0; margin-right:10px; border: 1px solid #dfdfdf; padding: 0em 1em 1em 1em; background-color:#F8F8FF; align:right;">

The Intel 2 Core is the successor of the [[Intel Core Duo (Yonah)]] processor. Unlike the Yonah, the Merom was designed specifically with mobile applications in mind. The Merom introduced various architectural additions such as EM64T, [[SIMD|SSSE3]] and improved the performance by up to 25 percent. The 667 MHz FSB versions are part of the "Napa" platform, while the 800MHz FSB versions are part of the "Santa Rosa" platform. The chip is also part of the hardware from both the Centrino Duo and Centrino Pro brands.

=Features=
*Dual Core
*EM64T
*[http://en.wikipedia.org/wiki/Vanderpool#Intel_Virtualization_Technology_.28Intel_VT.29 Intel Virtualization Technology ]
*XD-Bit
*[[SIMD|MMX]], [[SIMD|SSE]], [[SIMD|SSE2]], [[SIMD|SSE3]], [[SIMD|SSSE3]] instruction sets
*667 or 800 MHz FSB
*65 nm fabrication process
*4 MB or 2 MB L2-Cache with dynamic cache sizing
*[[SpeedStep|Enhanced Intel SpeedStep (EIST)]], power states: normal (C0), AutoHALT/MWAIT (C1), Stop Grant (C2), Deep Sleep (C3), [[QuickStart and Deeper Sleep|Deeper Sleep]] (C4)
</div>
|}

=Available Types and ThinkPads featuring them=
==Standard Voltage==
{| border=1 cellspacing=0 cellpadding=2
|- style="background:#ffdead;white-space:nowrap;"
! Nr. || colspan=2 | Frequency (MHz) || L2 Cache || FSB (MHz)|| VT || colspan=2 | core Voltage (V) || colspan=2 | TDP (W) || ThinkPad Models
|- style="background:#ffdead;"
! !!max. !! min. !! !! !! !! high !! low !! high freq !! low freq !!
|-
| T8300 || 2400 || 800 || 3MB || 800 || yes || 1.25 || 1 ? || ? || ? || {{X61}}, {{T61}}, {{R61}}
|-
| T7800 || 2600 || 1000 || 4MB || 800 || yes || 1.30 || 0.85-0.9 || 35 || ? || {{T61p}}
|-
| T7700 || 2400 || 1000 || 4MB || 800 || yes || 1.30 || 0.85-0.9 || 35 || ? || {{R61}}, {{T61}}, {{T61p}}
|-
| T7600 || 2333 || 1000 || 4MB || 667 || yes || 1.30 || 0.95 || 34 || 20 || {{T60}}, {{T60p}}
|-
| T7500 || 2200 || 1000 || 4MB || 800 || yes || 1.30 || 0.85-0.9 || 35 || ? || {{R61}}, {{T61}}, {{X61}}
|-
| T7400 || 2166 || 1000 || 4MB || 667 || yes || 1.30 || 0.95 || 34 || 20 || {{T60}}, {{T60p}}, {{Z61t}}
|-
| T7300 || 2000 || 800 || 4MB || 800 || yes || 1.30 || 0.85-0.9 || 35 || ? || {{R61}}, {{T61}}, {{X61}}
|-
| T7200 || 2000 || 1000 || 4MB || 667 || yes || 1.30 || 0.95 || 34 || 20 || {{R60}}, {{T60}}, {{X60}}, {{Z61m}}, {{Z61t}}
|-
| T7100 || 1800 || 1000 || 2MB || 800 || yes || ? || 0.85-0.9 || 35 || ? || {{R61}}, {{T61}}
|-
| T5670 || 1800 || 800 || 2MB || 800 || yes || 1.30 || 0.95 || 35 || ? || {{SL300}}
|-
| T5600 || 1833 || 1000 || 2MB || 667 || yes || 1.30 || 0.95 || 34 || 20 || {{R60}}, {{T60}}, {{X60}}, {{Z61t}}
|-
| T5500 || 1666 || 1000 || 2MB || 667 || no || 1.30 || 0.95 || 34 || 20 || {{R60}}, {{T60}}, {{X60}}, {{Z61m}}, {{Z61t}}
|}

==Low Voltage==
{| border=1 cellspacing=0 cellpadding=2
|- style="background:#ffdead;white-space:nowrap;"
! Nr. || colspan=2 | Frequency (MHz) || L2 Cache || FSB (MHz)|| VT || colspan=2 | core Voltage (V) || colspan=2 | TDP (W) || ThinkPad Models
|- style="background:#ffdead;"
! !!max. !! min. !! !! !! !! high !! low !! high freq !! low freq !!
|-
| L7400 || 1500 || 1000 || 4MB || 667 || yes || 1.2 || 0.85 - 0.9 || 17 || ? || {{X60s}}, {{X60_Tablet}}
|-
| L7500 || 1600 || 800 || 4MB || 800 || yes || 1.1 || 0.85 - 0.9 || 17 || ? || {{X61s}}, {{X61_Tablet}}
|-
| L7700 || 1800 || 800 || 4MB || 800 || yes || 1.1 || 0.85 - 0.9 || 17 || ? || {{X61s}}, {{X61_Tablet}}
|-
| SL7100 || 1200 || 800 || 4MB || 800 || yes || 1.1 || 0.85 - 0.9 || 12 || ? || {{X300}}
|}

As you can see, the Low-Voltage CPU's work at the same Voltage as the normal CPUs when running in SLFM. With a simple tool (RMClock) you can use those lower voltages at every clock.
Intel gave other voltage-regions for the CPUs:

''the standard processor that works on a core voltage between 1.075V and 1.175V, the low voltage processors that work between 0.975V and 1.062V and finally the ultra low voltage processors that work between 0.80V and 0.975V.''

Intel doesn't think of the SLFM. With SLFM and a little bit luck, you're T-CPU can be thriftier than a LV-CPU but has more power.
With RMClock every T-CPU is thriftier than a LV-CPU, because you have the same voltage but a higher max-clock, so the sleep-states can be longer.

=Thermal Specifications=
The maximum temperature for safe operation is 100°C.

The catastrophic thermal protection temperature is 125°C.

Idle temperature is typically around 30-50°C.

Temperature at full utilisation is around 60-70°C.

These latter two values will of course depend largely on cooling systems and available airflow.

=Compiler optimisation flags=
==GCC==
In addition to the architecture independent <code>-O[0123s]</code> option hierarchy, architecture dependent optimisations are controlled by the <code>-march=<cpu-type></code> and <code>-mtune=<cpu-type></code> options. The <cpu-type> argument (not surprisingly) describes the type of cpu for which to optimise the compiled code. The <code>-mtune</code> option will generate code that is optimised for the given cpu type which will nevertheless run on cpu types other than the optimisation target. On the other hand, <code>-march</code> will attempt to optimise more aggressively at the expense of reducing portability to other cpu types. Optimisations implied by <code>-mtune</code> are a subset of <code>-march</code> optimisations, and thus it is only necessary to specify <code>-march</code> if the the maximum level of optimisation is desired.

With version of gcc before 4.3, 32-bit code should be compiled with the "prescott" as the cpu-type argument to <code>-march</code> or <code>-mtune</code> whereas 64-bit code should use the "nocona" argument. Gcc 4.3 however introduces "core2" as a valid argument to the <code>-mtune</code> and <code>-march</code> options which should be used. Alternatively, as of gcc 4.2, the "native" argument is supported. This will automatically determine the cpu-type on which compilation is taking place and apply optimisations specific to that cpu.

==Intel==
For the [http://www.spec.org/cpu2006/ SPEC CPU 2006 benchmarks], Intel used the shorthand <code>-fast</code>, which translates into <code>-O3 -ipo -static -no-prec-div -xP</code>. However, the compiler also provides the flag <code>-xT</code>, which activates the optimization for Core 2 Duo and SSSE3 (instead of SSE3 only with <code>-xP</code>).

=Microcode=
Much like software products, bugs, errata or ways to improve upon operation are often found in CPU's after they have reached the market. In some cases, the necessary changes can be applied by the end user without any change to the underlying hardware in the form of microcode updates downloadable from the manufacturer. Intel offers these microcode updates for download on their [http://downloadcenter.intel.com/Detail_Desc.aspx?ProductID=2676&DwnldID=14303&lang=eng website].

Provided the availability of the <tt>microcode</tt> and <tt>firmware</tt> kernel modules (which are enabled in the stock kernels of most distributions) and a suitable user space tool such as [http://urbanmyth.org/microcode/ microcode_ctl], one can install the updated microcode into their processors at runtime. The microcode update is volatile however, meaning that it disappears upon reboot. While this reduces the risk of applying such an update to essentially 0, it does mean that it must be applied on each boot.
==Debian==
You can install the microcode.ctl package which will take care of everything (including downloading the microcode itself) for you. Just run
{{cmdroot|aptitude install microcode.ctl}}. This package includes an init script which will run at boot to load the microcode into the processor. This script also contains a line which will remove the <tt>microcode</tt> kernel module once the operation is complete and it is no longer needed, however it is strangely commented out by default. If you want to keep your loaded modules (used memory) to a minimum, you can edit {{path|/etc/init.d/microcode.ctl}} and uncomment the line
<pre>
[ -x /sbin/modprobe ] && /sbin/modprobe -r microcode > /dev/null 2> /dev/null
</pre>
==Gentoo==
The <tt>microcode-ctl</tt> utility can be installed as follows: {{cmdroot|emerge microcode-ctl}}. This will create an init script <tt>/etc/init.d/microcode_ctl</tt>, but will not automatically set it to run on startup; to do so, run {{cmdroot|rc-update add microcode_ctl boot}}. Also, this will install an old copy of the microcode to <tt>/etc/microcode.dat</tt>; to update it, download a new copy from the link above and replace this file.

=Note on Hyper-Threading=
Note that as opposed to Pentium 4/NetBurst, current Core 2 do not support hyper-threading, and therefore there is usually no option in the BIOS to activate it. Refer to Intel's [http://www.intel.com/products/ht/hyperthreading_more.htm Hyper-Threading Technology] for a list of hyper-threading capable CPU.

=See also=
[[Intel_Core_Solo_(Yonah)|Intel Core Solo (Yonah)]]

[[Intel Core Duo (Yonah)]]

== External Links ==
*[http://www.intel.com/products/processor_number/chart/core2duo.htm Intel - Processor Numbers and Features]
*[http://en.wikipedia.org/wiki/List_of_Intel_Core_2_microprocessors#Mobile_processors Wikipedia - Intel Core 2 mobile microprocessors]

[[Category:Components]]

Category:SL Series

2009-01-18T22:00:57Z

Fthieme: /* Hardware */

{| width="100%"
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<div style="margin: 0; margin-right:10px; border: 1px solid #dfdfdf; padding: 0em 1em 1em 1em; background-color:#F8F8FF; align:right;">
{||
|
=== ThinkPad SL Series ===
This page gives an overview of all ThinkPad SL Series (SL300, SL400, SL500) related topics.
|{{WARN|The SL Series-notebooks have IdeaPad firmware, they are not ThinkPads as far as Operating System support (i.e. drivers) are concerned.}}
|}

=== Hardware ===

*CPU
**Intel Core 2 Duo
***Works without problems (tested on 2.6.27).

*Graphics Hardware
**integrated Intel X4500HD
***Works without problems (tested on 2.6.27).
**Discrete NVIDIA GeForce 9300 graphics
***Unknown, but should work with the proprietary nVidia driver

*Displays
**13,3" - 15,4" TFTs
***Work without problems.

*Interface ports
**USB
***Work without problems.
**FireWire
***Unknown, but should work.

*Network interfaces
**WLAN
***Intel WiFi Link 5100: Works without problems (iwlagn) (tested on 2.6.27 with 802.11g)
***Atheros AR5007EG chipset: ath5k should work since 2.6.27 (but I encountered problems connecting to networks). madwifi with proprietary driver is more reliable. See these [http://www.thinkwiki.org/wiki/Install_Ubuntu_8.10_(Intrepid_Ibex)_on_a_Thinkpad_T400 instructions]. Use [http://ubuntuforums.org/showthread.php?t=939107 script] to remove module before suspend/hibernate and reload after resume/thaw.The wireless switch on front of case does work, but the wireless LED doesn't light up.
**WWAN
***Intel WiMAX/WiFi Link 5350 (UMTS/HSPA): Detected, but I couldn't make it connect (2.6.27)
**LAN
***Realtek RTL8111/8168B gigabit ethernet: works (tested at 100Mbit).
**Bluetooth 2.0
***Integrated chipset: Detected, but not tested (2.6.27)

*ACPI
**Suspend (s2ram)
***Works (2.6.27). For 2.6.26 and earlier, use command "s2ram -f -s".
**Hibernate (s2disk)
***Works (2.6.26).
**Battery state
***Detected if only battery is used or not. (2.6.27)
***Battery stage not very exact / maybe completely wrong (2.6.27). Powertop is more accurate than Gnome battery applet.

*Other stuff
**Fingerprint reader
***Not detected (2.6.27)
**Webcam
***Detected, seems to work (can stream videos) (2.6.27)
**HDASP
***Not detected.

*Hotkeys
**Buttons for ThinkCare, Volume up, Volume down, Mute in the upper left corner
***Don't work (2.6.27), no keycode shown in xev.
**Fn combinations (if keycode exists, then can be made to work by [http://cweiske.de/howto/xmodmap/allinone.html reassigning keys] in /etc/Xmodmap)
***SysRq (Fn+F1): Prints screen.
***Lock Screen (Fn+F2): No keycode.
***Manage battery & power (Fn+F3): No keycode.
***Suspend (Fn+F4): Works. If 2.6.26 or earlier, resumes without screen--press Ctrl+Alt+F1, then Ctrl+Alt+F7.
***Wlan (Fn+F5): No keycode.
***Print Screen (Fn+F6): Works.
***LCD/External Monitor (Fn+F7): No effect in Debian Lenny with both screens aways displayed (keycode 214).
***TrackPointer/Touchpad (Fn+F8): No keycode.
***Manage external devices (Fn+F9): No keycode.
***No function (Fn+F10): Same keycode as F10.
***Pause (Fn+F11): Works? (keycode 110)
***Hibernate (Fn+F12): No keycode
***Screen Lock (Fn+Insert): Doesn't work (keycode 78)
***Number Lock (Fn+Delete): Works, but the Number Lock LED on right side of keyboard doesn't light up.
***Brightness Down (Fn+Home): Inverted--sets screen brightness up (keycode 101). (Patch available: [http://bugzilla.kernel.org/show_bug.cgi?id=12037])
***Brightness Up (Fn+End): Inverted--sets screen brightness down (keycode 212).
***? (Fn+PageUp): Doesn't work (keycode 234)
***? (Fn+PageDown): Doesn't work (keycode 233)
***Stop (Fn+UpArrow): No keycode.
***Pause/Play (Fn+DownArrow): No keycode.
***Play Previous (Fn+ArrowLeft): No keycode.
***Play Next (Fn+ArrowRight): No keycode.
***Magnify Screen (Fn+Space): No keycode.

Ultracampatch

2007-08-12T18:29:24Z

Fthieme: /* Project Homepage / Availability */

==IBM UltraCam II driver==
Kernel patch to enable support for the IBM UltraCam II.

=== Features ===
* camera working on USB and Ultraport
* supports the basic functions of the camera
* automatic white balancing

=== Project Homepage / Availability ===
*[http://www.gutwin.org/cam/source/index.html patch for kernel 2.4.20]
*[http://marc.theaimsgroup.com/?l=linux-usb-devel&m=111802180804300&w=4 patch for kernel 2.6.10]
*[http://sourceforge.net/mailarchive/message.php?msg_id=20060912211346.2a00df3a%40parabelbox patch for kernel 2.6.18]
*[http://sourceforge.net/mailarchive/forum.php?thread_name=200708122008.29215.frank%40fthieme.net&forum_name=linux-usb-devel patch for kernel 2.6.22.2]

=== Status ===
usable, but unstable, project seems to be dead

The current driver gives a 320x240 image, with White Balance control (optionaly automatic).
Contrast, and importantly Brightness Control have not been implemented, so the camera is ultra-sensitive to light; you may find you have to walk into a wardrobe to see a picture during the daytime.
The driver has been included with the kernel since circa 2.4.21 (I don't remember the exact version)

The present driver also needs updating to include proper support for sysfs, so having removed the camera while running Linux with sysfs, you will have to restart the system to get the camera working again (until sysfs support is added tothe driver).

=== Interesting links related to this project ===

*[http://linux.bytesex.org/v4l2/ Video4Linux Project Home]
*[http://www.exploits.org/v4l/ Video4Linux Resources]

[[Category:Drivers]]

Intel Mobile Pentium III-M

2007-07-14T11:20:26Z

Fthieme: /* GCC Optimization Flags */

Problem with fan noise

2006-12-26T21:33:57Z

Fthieme: /* Software solution - Linux */

Information about the fan noise problem in Thinkpad models from 2003/2004/2005.

==Problem description==

There seem to be two different issues causing annoyance from fan noise:

===Acceleration (pulsing) problem===
The Thinkpad fan briefly accelerates in regular intervals (every few seconds), causing an annoying periodic pulse noise.

See [http://lophiomys.gmxhome.de/Thinkpad_R50_Periodic_Fan_Noise.html here] for audio recordings of this noise on ThinkPad {{R50}} and {{R51}}.

===Always-on problem===
The fan is always on, even when the laptop is rather cool.

==Affected Models==

===Acceleration (pulsing) problem:===
*ThinkPad {{600E}}
*ThinkPad {{R40}}
*ThinkPad {{T40}}, {{T40p}}, {{T41}}, {{T42}}, {{T43}}

===Always-on problem:===
*ThinkPad {{600X}}
*ThinkPad {{770X}}
*ThinkPad {{A31p}}
*ThinkPad {{R32}}, {{R50}}, {{R50p}}, {{R51}}, {{R52}}
*ThinkPad {{T40}}, {{T40p}}, {{T41}}, {{T41p}}, {{T42}}, {{T42p}}, {{T43}}, {{T43p}}, {{T60}}
*ThinkPad {{X32}}, {{X40}}, {{X41}}, {{X60}}
*ThinkPad {{Z60m}}
*ThinkPad {{Z61m}}

==Affected Operating Systems==

===Acceleration (pulsing) problem:===
*All operating systems (this is a firmware bug). Note that some vendors might ship with fan-control workarounds enabled by default.

===Always-on problem:===
*Linux, all flavours
*FreeBSD 5.3
*OpenBSD 3.7 (Tested with X40)
*Windows XP
*Windows 2000 pro

==Status==

===Acceleration (pulsing) problem:===
The pulsing is triggered by the embedded controller when it monitors the fan speed and adjusts the fan control accordingly every few seconds.

For some models, IBM released an update to the embedded controller program that seems to at least partially solve this problem:

Version 3.03 - 1RHT70WW
NOTE: This version of Embedded Controller Program will only work with BIOS Version 3.06f (or higher).
* (Fix) Reduced Fan noise in some models.

The update can be found here: http://www-306.ibm.com/pc/support/site.wss/document.do?lndocid=MIGR-50279

Unfortunately, this update was not correctly ported to the Thinkpad {{T43}} and {{R52}} firmware: someone made a careless typo which generally results in no improvement in behaviour: the fan may continue to pulse every ~4.8s, and for some it may accelerate a great deal every 30 seconds or so, making a lot of noise. An unofficial patched firmware exists in source code format (see below).

For models which still have broken firmware (e.g., ThinkPad {{T43}} with official firmware), there is a software workaround (see below).

===Always-on problem:===
The problem is yet unsolved. But see the partial fix below.

IBM made a statement regarding this on their homepage:
http://www-307.ibm.com/pc/support/site.wss/document.do?sitestyle=lenovo&lndocid=MIGR-56504

==Solutions==

===Acceleration problem:===

====Replacing the fan====
Some people reported that they replaced the original fan against one of a similar notebook without the problem has worked for them, i.e. changing a {{T41}}s fan against one from a {{T41p}}.

====BIOS upgrade====
For relevant models, you can try upgrading your embedded controller program to version 3.03 or newer.
The update can be found here: http://www-306.ibm.com/pc/support/site.wss/document.do?lndocid=MIGR-50279

Also, in late November 2005 IBM released a BIOS and embedded controller update (BIOS 1.24, EC 1.04) for the T43/p
(Machine types 2668, 2669, 2678, 2679, 2686, 2687). Reported results are not consistent and range from cooler sensor readings (some sensors seem to report lower temperatures with this patch), less fan pulsing (also only reported by some users), and slightly different fan behaviour.
The link to this update is: http://www-306.ibm.com/pc/support/site.wss/document.do?sitestyle=ibm&lndocid=MIGR-58597#bios

====Fixing the firmware====
For T43/R52 firmwares 1YHT29WW and 70HT28WW, a fix is available and known to work, but it is not easy to deploy. You have to know enough to modify the firmware yourself. The fix is in the firmware source code (but disabled by default), see [[Embedded Controller Firmware]] for some information to get you started. If you are not at ease programming microcontrollers, please stick to the software workarounds, there's a reason this fix is not just an easy download away.

====Software workaround====
The problem can be solved through appropriate modulation of the embedded controller, using an [[ACPI fan control script#Variable speed control scripts|ACPI fan control script]].

===Always on problem:===

====Reducing power consumption====
Generally, this problem is triggered by heating due to high power consumption. See [[How to reduce power consumption]].

It seems like for some people a combination of enabling dynamic frequency scaling and using the most recent radeon drivers (from xorg 6.8.x) with the DynamicClocks option enabled helped lowing the fan rotation and hence making it more quiet.

Also the fglrx driver from ATI is said to show the same effect when used together with dynamic frequency scaling.

I can confirm that on my R51, the graphics card seems to be the problem. The fan keeps running most of the time even with AC on, but even though I activated DynamicClocks (with the radeon driver), I can see in /proc/acpi/ibm/thermal that the GPU (4th value) is at 52-53Â°. The fan stops running as soon as the temperature gets down to 50 degrees and starts again at 53. While debugging, I seemed(!) to be able to reduce the temperature together with the resolution (e.g. "xrandr -s 2" to get from 1400x1050 to 1024x768) or by switching off the graphics with "xset dpms force off". The bottom line is that the below "partial fix" won't work because the GPU temperature is the problem.

The GPU also seems to be the culprit on the t43p. Even with the fan always on (with speeds of around 4K reported in /proc/acpi/ibm/fan), the temperature never drops below 55. This is with the Xorg driver and DynamicClocks=on. With the ATI's fglrx driver, the GPU temp seems slightly higher (although I haven't performed a careful comparison). Without the fan, the temperature very quickly climbs to above 60.

With the Pentium M, CPU heat dissipation can be reduced through [[Pentium M undervolting and underclocking|undervolting and underclocking]].

In regard to the technical side of controlling the fan, see [[How to control fan speed]] for a description of the embedded controller byte at offset 0x2F which controls the fan activity (T4X series and other later models). In addition to these in the discussion to this topic [http://www.thinkwiki.org/wiki/Talk:Problem_with_fan_noise] a user observed hidden temperature sensors. In the ACPI DSDT dump a {{T43}} reports 8 temp values at offset 0x78 (some of which may be off and yield a constant value of 0x80), but there are at least three more values at offset 0xC0 which from observation seem to show temperatures as well. One of these sensors (0xC1) is most likely in the area of the mini PCI slot (related to WLAN activity) and seem to trigger the fan at 43Â°C ({{T43}}, Windows XP). Another one (0xC2) seems to be located below the power supply (rear left, in the area under the Esc, F1-F3 keys). This one noticeably increases when the battery is charged. Both, the 0xC1 and 0xC2 react quite slowly to fan activity.

For more information about the thermal sensors that are monitored to decide the fan speed, see [[Thermal sensors]].

====Software solution - Windows====
{{WARN|This circumvents the BIOS fan control, so be careful and use at your own risk! Don't toast your ThinkPad.}}

The ThinkPad Fan Control Utility (http://sourceforge.net/projects/tp4xfancontrol/) actively monitors the CPU Temperature and uses ACPI to manually control the fan speed. It was written for the T43, but works on a number of other models as well. A port of this programme running as a Windows service is available from http://www.cceye.com/index.php?topic=73.0 (download: http://www.cceye.com/index.php?action=dlattach;topic=73.0;id=9 ). Extensive discussion of this utility is available at http://forum.thinkpads.com/viewtopic.php?t=17715

The version which runs as a Windows service is recommended because the system will restart it if the programme crashes. A crash of either programme could leave your computer without any active cooling, leading to overheating and potentially serious damage.

ref links
http://www.thinkwiki.org/wiki/Problem_with_fan_noise
http://forum.thinkpads.com/viewtopic.php?t=17715

Note:
1 The Windows Event log will fill up with repeated errors regarding the Embedded Controller: please clean your event log regularly.
2 The programme may crash from time to time, but the service version should restart after a crash.

====Software solution - Linux====

See [[How to control fan speed]].

{{WARN|This circumvents the BIOS fan control, so be careful and use at your own risk! Don't toast your ThinkPad.}}

I had this problem on my X24 by using a stock Debian Etch kernel. I solved it by compiling an unpatched kernel myself and leaving the fan module out. But I guess the fan module wasn't responsible for, because the fan started to run before modules were loaded.

====Cleaning the fan or removing obstructions====

If your ThinkPad is old or has been exposed to dusty environment, it is possible that accumulated dirt on the fan and the heatsink cause abnormal behavior (though the problems have also been reported for brand new units). You can use a combination of a vacuum cleaner and an air dusting spray to clean things up from the outside. Bigger agglomerations of dust may require removing by tweezers through the openings in the fan grill. Getting to the fan itself from the inside is quite tricky and may require removing the keyboard or LCD - see [[Maintenance#Cleaning_the_Interior|Cleaning the Interior]].

If the fan is especially noisy, there may be some obstruction other than dirt in the way. For instance, in some ThinkPad models, a wire that is not properly taped down can become draped over the CPU fan, slowing down fan rotation and emitting a loud buzzing sound. Moving such an obstruction out of the way can greatly decrease fan noise.

After you clean things up, power on your ThinkPad. You should hear the fan start up for a bit when booting. If it does not, this means that the cleaning procedure has actually blocked the fan and your computer will overheat at some point (BIOS POST test does not appear to catch obstructed fans). Keep cleaning.

If cleaning does not fix the problem, the fan can be replaced as described in your laptop's appropriate Hardware Maintenace Manual: select your laptop at the [[Models#Available Models|Models Page]] and follow the links. All that is generally required is some screwdrivers and heat sink thermal grease. Do NOT attempt to install without the silicon grease.

If you feel comfortable using a soldering iron, you are more than qualified to do the procedure. Just remember do NOT force anything, at several steps there are tiny plastic "tabs" that can break off necessiting a more expensive bezel / keyboard / GPU replacement.

====Hardware modification====
An extensive forum discussion of this problem for the ThinkPad {{T43}}/{{T43p}}, and possible hardware mods for thermal enhancement, appear [http://forum.thinkpads.com/viewtopic.php?t=14580http://forum.thinkpads.com/viewtopic.php?t=14580 here]. There users who had opened the machine reported uncooled Northbridge and Southbrige chips, having no physical connectino to the heat pipe. Building a hardware copper bridge to these did change the temperature characteristics but did not cure the "always on" problem. In an other discussion on that forum a user said that amongh other areas the WLAN chip may be responsible for generating extra heat and that disabling WLAN (among other unused devices) may help.