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My reported System Temperature (when idle) is considerably higher than all other reported temps on my (new) machine. When Sys Temp is 51C, other reported temps are:

  • GPU is 36C
  • CPU is 27C
  • HD0(SSD) is 30C
  • HD1 is 33C
  • Two other (unknown) temps report 28C and 30C - These would seem to be the "ACPI" temps.

Ambient room temp is 25C.

Fortunately, the Sys Temp does not increase by much under heavy load... I've seen a max of 58C running Prime95 for an hour (whilst the CPU temp reached 70C max). So, I've not been too worried, however, I cannot help but feel this is too high for idle!?


  • Intel i7-4770k 3.5GHz (not overclocked)
  • Corsair H60 liquid cooler (Pump connected to "CPU Fan" and corresponding fan connected to "Sys Fan")
  • Gigabyte GA-Z87N-WIFI motherboard --> Does this just run "hot"?!

When the machine is first booted (cold boot - first thing in the morning), the reported "System Temperature" is a reasonable 36C. However, over the next 10-15 mins (in an idle state), this temperature will steadily increase to stabilise at 51C. Unsurprisingly the Sys Temp controls the Sys Fan and when the temp creeps over 50C the BIOS has a "panic" and ramps the system fan up from about 1000rpm to 2000rpm (max) - which is a bit too noisy! Fortunately I can use SpeedFan to keep the temp at 51C (at 1300rpm) under normal working conditions and that's nice and quiet. But 51C seems warm to me!

The "System Temperature" does not appear to cool particularly quickly. Throughout the day, if I was to reboot, I have only seen the temperature drop to about 48/49C. (I originally thought this was the lowest/starting temperature until I cold booted the machine this morning.)

The same temps are reported by SpeedFan, HWMonitor, and in the BIOS.


  1. Is 51C too hot (for my motherboard)?
  2. What exactly is the Sys Temp monitoring!?
  3. Why is the Sys Temp so much higher than all the other temps (when idle)?
share|improve this question
It's not dangerously hot, but it is odd. Could be chipset (northbridge) temperature maybe? – user55325 Sep 30 '13 at 0:56
@user55325: Thanks. As mentioned in comments below, maybe this is just terminology, but I thought all "northbridge" components are incorporated into the processor these days? However, I do see ab "Intel Z87" chip (the "chipset"?) on the motherboard layout, which is covered by a small heatsink. – w3dk Sep 30 '13 at 9:15
Not *all northbridge components. Just some such as the memory controller and sometimes some of the PCI-e lanes. The rest is either still present as north- and southbridge, or jointy integrated in one chip. – Hennes Sep 30 '13 at 9:59
up vote 2 down vote accepted

1: 51 degrees C is a bit warm but nothing to get too riled up about. This is frequently the Northbridge temperature and since your specific motherboard doesnt have a fan on the northbridge it makes sense the temps would be a little higher than normal. To put the temperature into perspective the i7-4770k processor that you have is stable well into the 80 degree Celsius range (but not recommended).

2: The sys Temp. as I mentioned is usually the northbridge.

3: The northbridge is always working, even when you think the computer is idle, all the disk IO, graphics, Wifi etc, run through there, so it's always doing something.

It would be fairly trivial to add a fan or reposition an existing fan to make sure the Northbridge is getting enough airflow.

I would recommend adding a small fan that blows over the northbridge, but it's probably okay without it also.

share|improve this answer
Maybe just terminology, but I thought all northbridge components are incorporated into the processor these days? Although I do see "Intel Z87" on the motherboard layout, which is covered by a small heatsink. – w3dk Sep 30 '13 at 9:06
Thanks, having since chatted with a few others, this relatively high system temp seems to be reasonably common/normal for this particular configuration... H60 Cooler, GA-Z87N-WIFI motherboard and SFF case (Fractal Design Node 304). The system temp sensor is apparently in a position that doesn't get much airflow. I had previously tried running it without the case on, but that made little difference. However, I have since bought an additional spot fan so I'll see how it goes. – w3dk Oct 12 '13 at 12:29
Well done for doing your research! – tbenz9 Oct 13 '13 at 2:37
@tbenz9, Wouldn't 80 degree Celsius burn right through your skin if you try to touch it? – Pacerier Jun 5 '15 at 6:18

The reported temperature is probably the motherboard ACPI temperature. Some motherboards may report a temperature that is some 10-20 degrees higher than it really is, resulting in this unexpectedly high value.

Even if the reported "System Temperature" is correct, it's unlikely this is high enough to damage your hardware even if sustained over time. I wouldn't worry about it.

share|improve this answer
Thanks. I should add that on a cold boot (machine left off overnight) then the temperature immediately after booting is a far more respectable 36C. (I've only had the machine a few days - so this morning was the first I actually witnessed this.) However, over the next 10-15mins (of being idle), the temperature will slowly increase until stabilising at the stated 51C. – w3dk Sep 30 '13 at 9:22
On closer inspection of the SpeedFan config, it would seem that my reported "System" temperature is not the ACPI temperature. There are 2 other ACPI temperatures reported (which I'd stated as "unknown" in my question), these are 28C and 30C respectively. However, in the SpeedFan front screen they only show as "Temp1" and "Temp2". – w3dk Sep 30 '13 at 12:36

My previous PC had a similar issue, even at Idle it would report a system temperature of 61C. After replacing the PSU (after the old one was seen sparking) this was reduced to 45C. Both were ~500 watt, so I think it was an efficiency issue, not a power issue.

share|improve this answer
Wow, what a difference! But if it was sparking then there was definitely a problem with efficiency! lol. (Maybe also an airflow issue with the fans on the PSU?) I supposedly have quite an efficient PSU as it happens (80PLUS certification). – w3dk Nov 18 '13 at 11:46

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