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How high temperatures can screw your Mac

Special collaboration by Caio Ferrari.

Apple Power Mac G5This past weekend, I received a Power Mac G5 to fix. The imposing tower, purchased in 2004, presented locks whenever it was required but it was not a simple kernel panic, it was really a crash, without the right to explain. HD? Okay. Memory? Ok. System reinstalled and the problem persisted.

When monitoring the system temperature, I realized that when the processors were close to the temperature limit (63C), the machine would lock up. The fans were working well, so much so that the temperature didn't even reach the limit, it just got high.

I opened the machine and put a fan blowing air in there: the temperature was about 8C lower and the problem was apparently solved. Another solution was to slow down the processor speed on the panel Energy Saver System Preferences. When searching the Apple.com forums, I realized that the common problem and the solutions found, most of the time, were changing the processor and motherboard.

According to the description, anyone who works with electronics and knows computers must have killed? Cold welding!

Cold solder is the name given to the solder which has already lost its ability to conduct energy well. It has an opaque appearance and sometimes has ?latches? at the base. One of the reasons for its high temperature appearance. This heats / cools the metal because of the expansion and contraction that occurs in the temperature change (understand "stress" as the mechanical effort, like breaking a wire by flexing it repeatedly).

This problem was very common in CRT monitors (including Apple) and could be solved just by re-soldering the board while the assistants, often without having technicians in electronics, changed the board, which was obviously more expensive.

Unfortunately the cooling system of the G5privilegiao is silent, thanks to Steve Jobs' eternal freshness with fans and, moreover, it cannot be controlled via software, as in Intel Macs. The solution of the machine would be to make it work colder, since the exchange of components does not compensate for the price, either by circumventing the temperature sensor system so that the fans work faster, or by adding additional ventilation or, in the worst case , leave the machine at reduced speed.

Lucky for those with an Intel Mac, where speed control of fans can be done via software like smcFanControl2. Maybe you say that Apple engineers know what they are doing and that you shouldn't worry about it. Beautiful phrase, theoretically correct and perfectly applicable, if we were in a country where an iMac cost less than eight minimum wages and we had no problems with technical assistance.

The fact that semiconductors work well when cold. Precisely for this reason, it is invested both in cooling with sinks, fans and, in high-responsibility machines such as servers, they are usually stored in rooms with air conditioning equipment that not only serves to ?balance? the heat generated by the machines, but also to keep the room cool enough that you need a sweater to stay there.

I did some tests on my iMac Intel Core 2 Duo, increasing the speed of the fans while I played. I made the CPU and HD fans about 1,000RPM faster than they are when they are managed by the system. In both cases, I played the same game during the same period:

Comparison of temperatures

In the images you can see that the temperature of the video card dropped by 20C! Meanwhile, the processor got 13C cooler and the HD, 7C cooler. And all this with the fans at a speed that is fully acceptable in terms of noise, even at night.

The benefits brought by the durability of the components are, without a doubt, very great. Therefore, I strongly recommend that users leave their machines preferably in well-ventilated places, where there is no direct sunlight and that, if they are going to do something that requires a lot of the machine (such as playing games), consider the possibility of increasing even if in a way Ventilation speed is sensitive to keep the temperature low.

Never too much caution.

(Text adapted from this topic of our FRUM.)