Background Information:
Those who own a Voodoo M:460 laptop will find it to be rather noisy due to its internal fan. If a CPU/GPU intensive application is running the fan will reach full throttle very quickly creating an unpleasant amount of sound. To solve this I resorted to the option described in this article.
I was originally under the impression that ATI's Mobility Radeon 9600 created most of the heat in the M:460. Even through the 9600 generates a good share of heat, the fan is there to cool Intel's Pentium-M processor.
Intel's SpeedStep, which can dynamically change the speed of the P-M processor, is a hardware feature controlled by software. This means that Windows tells the processor what speed it should run at depending on the situation. For example; if a game is loaded, Windows will automatically change the processor speed from the default idle (600MHz) to the maximum available speed (1.7GHz in my case).
The internal fan of the M:460 is triggered by heat; when the heat increases, so does the speed of the fan. Because 1.7GHz generates more heat than 600MHz, the fan must turn on to maintain a safe temperature for the processor. To override this, the processor speed must be kept somewhere in-between the highest and lowest setting. This makes it possible to play a game while not making enough heat to set off the fan.
SpeedswitchXP is a program for Windows XP that allows SpeedStep features to be controlled by the end user. I will be using this application to apply all changes to the power settings of Windows.
Instructions:
Download and install SpeedswitchXP
Once installed you will see a small flag in your system tray
Left-click on the icon to bring up the Main window
Click Detect max. speed (optional)
Click Options and check Read CPU Speed
Click the User Policy tab
In the Forced Throttle input boxes enter the percentage value that you want
| 35% |
600MHz |
| 47% |
800MHz |
| 58% |
1000MHz |
| 70% |
1200MHz |
| 82% |
1400MHz |
| 100% |
1700MHz |
Click OK
Using these settings SpeedswitchXP will run your processor at 600MHz when idle and then dynamically change the processor speed as needed. For example; if you entered 58% as the forced throttle value your processor will run at 600MHz when idle and 1000MHz during CPU intensive applications.
You may now click Close and the settings will remain active even when SpeedswitchXP is not running. SpeedswitchXP adds a power scheme under the power settings of Windows XP. If you wish to disable the settings you set you can simply change your power scheme to a default Windows scheme.
Results:
I used SiSoftware's Sandra 2004 arithmetic benchmark to test performance loss and fan state. Performance loss and fan state will vary in real world applications depending on the amount of CPU/GPU utilization. Since these benchmarks analyze CPU only scenarios, 3D applications may
yield
different results.
| Speed |
Fan State |
Performance Loss |
| 600MHz |
Always off |
70.5% |
| 800MHz |
Usually off, low |
53.0% |
| 1000MHz |
Intermittently on, low |
41.3% |
| 1200MHz |
Intermittently on, medium |
29.5% |
| 1400MHz |
Usually on, high |
17.7% |
| 1700MHz |
Always on, highest |
0.0% |
600MHz performs quite poorly offering no real advantage other than minimal power consumption. This setting produced undesirable results in video games making it difficult to play with 16+ bots. I would only use this setting if I were in desperate need of battery life.
800MHz does very well considering its 200MHz speed increase from 600MHz. Even though the performance isn't great, the fan is usually off making it a choice for those who enjoy their peace and quiet.
1.0GHz is the fastest quiet setting. The fan turns on only reaching the second or third speed but shuts off during less intense applications. This setting is definitely usable especially considering the performance loss is less than 50%.
1.2GHz, although slightly louder than 1.0GHz, all around is very reasonable. The fan turns on reaching medium speed and usually remains there for quite some time. The performance loss is acceptable in most cases but it is still noticeable.
1.4GHz has the least performance loss but the noise generated by the fan pushes tolerable. At this setting games are very playable but since the fan is almost always on it's worth it to skip this one and go straight for 1.7GHz.
1.7GHz provides the best performance but the fan is always on its loudest setting. If you want performance and can live with the noise just stick with this setting.
Conclusion:
I experienced a
notable
performance decrease in both CPU and GPU related tasks whenever I underclocked my processor. While still not anywhere near as fast as 1.7GHz, 1.0GHz seemed to have the best balance of performance and silence. 3D benchmarks such as AquaMark3 and 3DMark03 received less than 8% performance loss around 1.0-1.2GHz making this range ideal for less intensive
GPU oriented programs.
The bottom line is that you just can't have the performance of 1.7GHz and a quiet laptop with the current fan. This fan needs to make a lot of noise to keep the system cool and the only way to solve this is to degrade performance. In some cases it is possible to do this without a noticeable loss of performance, but how much noise you reduce is up to you.
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