How Accurate is CoreTemp?

[SenoritaCao]

I know that this question has been asked before and I have read some threads on CoreTemp but there's still something bothering me about it.

I read that CoreTemp usually reads temperatures that are higher than reality, but that seems a little ridiculous in my situation.

I'm using a FX-4300 with a Cooler Master Hyper 212 EVO and air temperature is around 25-30 degrees Celsius. When I'm idling, CoreTemp reports a temperature of...As low as 8 degrees Celsius.

Currently, I'm attributing this to the fact that TJ. Max is set at 90 degrees whereas other processors (Intel specifically) are set to be 105. Am I right in assuming this? Because if I offset the temperature by 15 degrees, the temperature readings I get become a lot more realistic (Though they still fall below room temperature periodically). Also, I only have fans in this case.

 

[Zerk2012]

Download Realtemp GT don't adjust anything.
http://tpucdn.com/realtemp/screen1.jpg

 

[coovargo]

Fairly accurate but you have to "Calibrate" it properly with the offset. The trick to using it is doing the following steps:

Boot your computer. Open the CoreTemp program. Write down the temperature in C. Shut down your computer and check the temp in the BIOS and take note on what it is. Find the difference between the temperatures. Put that value in your offset. Hopefully that will solve your issue.

CoreTemp is accurate for most configurations but there are still some situations when it can't give you the full picture. The odds of that are very low, unless you're using some unusual hardware. I had an 8350 and it would say I had a temp of 11 degrees Celsius on water cooling. Pretty insane. My offset being somewhere in the 20s. I can't recall at the moment. The other software I've used is AIDA64 but it didn't have accurate temps either.

 

[ShadyHamster]

Don't offset the temps, in fact i would avoid using core temp altogether to read amd temps since there are 2 temps you need to monitor.
You need to monitor the core and socket temps, and yes the core temps are never accurate while the pc is idling.
I personally use AIDA64 to monitor temps but there are others such as HWinfo or HWmonitor that will do just fine too.

 

[ShadyHamster]

Download Realtemp GT don't adjust anything.
http://tpucdn.com/realtemp/screen1.jpg

If only realtemp was compatible with AMD cpu's...

 

[SenoritaCao]

Download Realtemp GT don't adjust anything.
http://tpucdn.com/realtemp/screen1.jpg

If only realtemp was compatible with AMD cpu's...

My sentiments exactly. Though RealTemp reported 102 degrees on my old laptop. But it would make sense since the keyboard got to 60degrees and burned my fingertips...

 

[SenoritaCao]

Okay, I've checked the BIOS and it says about 40 degrees on the CPU and 30 on the motherboard. For the time being, I'll just offset CoreTemp by 30degrees so I get a minimum reading of about 38 degrees until I find another sensor.

Edit: Currently using HWmonitor and the temperatures look pretty accurate going off what I've seen on the BIOS. Shame I can't put the numbers on the taskbar so I can monitor temperature while I'm doing other things.

Double Edit: I'm getting very different temperature readings on the CPU from HWMonitor. The "ASUSTeK" tab reads CPU as 36-40 degrees celsius (Which is reasonable) but the "FX-4300" tab reads 9-26 degrees celsius (Which is what CoreTemp said). I think I should disregard the AMD reading since it appears the rest of the case is at 20-30degrees higher...

 

[mdocod]

What you have to understand here is that a core temp reading of an AMD FX chip is actually just an inversion of a thermal margin. It's not on an accurate scale relative to any real world temps, it's on it's own scale, and for all intents and purposes, uses it's own units of measure. The important thing is that it is very precise, so we can compare thermal margin readings (as long as they are being equally represented by software level interpretation) from chip to chip and know that the comparison is precise.

There's nothing unusual at all about sub-ambient core temp "readings" on piledriver chips. This is the norm for Trinity, Richland, and Vishera.

This is because the thermal margin is a calculated, not measured temp reading. When the CPU is leveraging power saving features that reduce clocks, or voltage, or gate off whole sections of the CPU (like C1E, and C6 state), it effects the way the thermal margin is calculated, which pushes the inverted temp reading to below ambient levels. It doesn't mean that your chip is actually below ambient temps. This is just a consequence of the way that the temp reading is generated.

Typically BIOS will be properly configured to read AMD temps for these chips on the "standard" scale. For Vishera, a 70C core temp reading aligns with 0 remaining thermal margin, and a 90C temp reading aligns with the critical/shutdown temp. For Trinity and Richland, the critical shutdown temp is 80C instead but the thermal margin maximum is the same. When you are in BIOS configuration, All of the cores kept in the highest power state with an "artificial" mild workload. If you read your temps in BIOS and assume that these are your real idle temps, and then go try to use this information to apply an offset, then you will be making a critical error, as the temp reading in BIOS is NOT an idle temp reading at all.