Is a "System Temperature" of 51 degC (123 degF) normal / OK?

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!?

Specification:

• 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.

So...

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)?

4 Answers

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.

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.

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.

As I saw through the internet, most people say "Current System Temperature" is a temperature of north bridge, but IMHO that's not truth! . As I tested my Gygabyte GA-P43T-ES3G mobo through putting a small 40mm cooler on the different point of mobo, I've found "System Temperature" falling down when I cooled South Bridge and some Realtec chip in SOP body right near the north bridge. As for north bridge there was totaly No effect of extra-cooling it. Also, OpenHardwareMonitor soft shows two temperature sensors on the mobo and reads them independently.