Requesting clarifications: CPU temp VS. System temp

gadgetzilla · Post by **gadgetzilla** » Thu Feb 14, 2008 8:36 pm

I have an antec fusion case. I have a CPU cooler and a 120mm fan on the cooler. The CPU fan is plugged into the 'cpu fan' connector on the motherboard. The motherboard has four pins whereas the Fan plug has only three. I was told not worry about that. The fan will just run at full speed ( which it does) all the time with the fourth pin not connected.

Question: What is the 'system' fan connector for on the motherboard ? and do I need do anything with it?

The antec fusion case has two 120mm fans on its side. They connect separately. Do people generally connect the 'case' fans to the 'system' connector on the motherboard?

In reading temp values, after having the pc on with no activity for 1hr then playing a 2 hr DVD, I read the following temps:

CPU: 22C / 71F
System: 33C / 91F

Are these values acceptable / normal ? and...what would be my next steps for lowering the 'system' temp ?

Thank you in advance for your help.
Gadgetzilla

tehcrazybob · Post by **tehcrazybob** » Thu Feb 14, 2008 10:21 pm

You correctly guessed the purpose of the 'System' fan header - you can plug a case fan in. This can allow you to control and monitor its speed.

As for your temperatures, they are both fine, and the CPU temp is exceptional. What type of processor are you running? If it's a newer Core 2, make sure to check it with the latest version of SpeedFan - older programs measure these processors 15c too low. Even then, you'd be at an acceptable temperature, though.

Often, the 'System' temperature would be a sensor somewhere on the motherboard reporting the internal temperature of the case. However, with a reading that high, I'd be willing to bet it's the chipset. That's a perfectly safe temperature for it.

Bluefront · Post by **Bluefront** » Fri Feb 15, 2008 2:29 am

The actual name of the fan header/sensor varies quite a bit. My Intel boards have a "SYS" temp as picked up by Speedfan that actually is a board sensor about 5mm above the CPU socket. Intel calls it the "Zone 1" temperature. The Intel Zone 2 temperature sensor is called "Ambient" by Speedfan, and is located well away from any MB hot spots. These boards also have a CPU temperature sensor that is correctly labeled by Speedfan.

There's no real across-the-board naming used by everyone....you have to figure it out for yourself.

jhhoffma · Post by **jhhoffma** » Fri Feb 15, 2008 7:39 am

Bluefront wrote:There's no real across-the-board naming used by everyone....you have to figure it out for yourself.

Or get an IR gun and measure for yourself for all the accuracy most of those temp sensors have!

yamahaSHO · Post by **yamahaSHO** » Fri Feb 15, 2008 7:39 am

CPU: 22C / 71F
System: 33C / 91F

What are you using to monitor these temps?

gadgetzilla · Post by **gadgetzilla** » Sat Feb 16, 2008 12:04 am

I'm reading temps at the BIOS level as well as from a utility that came with my GigaByte motherboard. The utility is called "Easy Tune 5".

In reading various other threads, seems that people are using a variety of different programs to monitor temps/RPMs.

One called "Core Temp" caught my attention. In running that and comparing with "Easy Tune 5", I was surprised to find a big difference.

Easy Tune5: 75F
CoreTemp: 91F

Why such a difference, and which one do you trust and go by?