Ambient Temps

8 Jan 2011
London, UK
I often read threads where people will quote their ‘idle’ temps. This will be in the context of any sort of setup: air cooled, AIO coolers, full on custom water builds of various size and complexity.

So I guess the ‘success’ of any given idle temperature is down to what the ambient room temperature is actually at.

And therefore it’s logical to conclude that the reporting of a good idle temp has a lot to do with the delta between the Ambient and Idle temps.

I’m running a 12900k at stock, on a three radiator watercooled system. I’m getting an idle of about 28-29 when ambient is at around 24-25. So a delta of 3-4 degrees depending.

From memory of the only other system I’ve owned (4790k also watercooled) I recall this one had a delta of around 2-3.

So I’m trying to figure out A) if my loop isn’t so good this time round (acknowledging I am trying out a more ‘silent’ config with the fans and pump) , B) whether my application of paste to CPU isn’t so good, or C) whether this chip just runs hotter than other CPUs - as I have read in numerous places.

So what’s the accepted theory and how should one approach this ‘analysis’? Cheers guys :)
Last edited:
8 Nov 2006
Any delta around 3-4 degrees with modern hardware, especially those new intel chips (most power hungry chips on market), is great.

So don't worry about it.

AMD on a big rad space loop might be 2-3 degrees at idle. My 5950x can see that sometimes. I've got 4 rads though.
28 Dec 2017
You're talking about several deltas also - ambient air to liquid to block/heatspreader to silicon.

I would focus on liquid temperatures when considering water cooling, as that's what you have control over in terms of fan speed, pump speed, radiator size.

Then the liquid to silicon delta is impacted by choice of block and flow rate, but also more importantly, your voltage and clock configuration. In other words once you've tuned your water cooling to the best setup you can, then it's time to look at your CPU temperatures idle and under load.

IMO I don't worry about idle temps at all as ultimately it's a tiny difference as you've highlighted, but also it's immediately thrown off if say your liquid and radiators are heat soaked after a long session.
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