What temperature reading does the CPU-fan use for control.

[U6b36ef]

What temp is being used to guide the CPU fan? It's probably best to set out the picture of what I am doing, and then what I am observing.

My PC case has 5V, 7V, and 12V settings for the case fans. In all monitoring, I am using the 5V settings. This runs case fans at the slowest, but still does a good job of cooling. The purpose of using minimal case cooling is specific. I want to know my CPU cooler will protect my CPU in any situation, under load like gaming. E.g. If I forget to switch up case fans. (Neither do I want to use any motherboard Asus BIOS fan tuning to make a more aggressive fan profile. I want the cooler to be independently sufficient.)

The CPU is an i5-4690, and is specced to T-case 72'C and Intel say add on 5'C for CPU core temp = 77'C. (http://www.tomshardware.co.uk/forum/id-1800828/intel-temperature-guide.html) I think that is max temp, but may be the CPU throttle of the boost clock.

Initially I was running a Freezer 7 Pro = max temps 66'C, (CPUID-Hardware Monitor). This wasn't brilliant but it was within spec. However I was only running games like Crysis 2 which were pushing the CPU to just 65% load. In all possibility a 100% load might exceed the CPU max temp.

I then bought a better cooler, the Noctua NF-U12S which gave = max temps 55'C, (CPUID-Hardware Monitor). Again this was under about 65% load. I think this cooler will probably protect the CPU under any situation, case fans low, CPU load full, etc.

Later after installing Asus AI Suite with Asus Probe II, I saw a vastly different CPU temp. Asus monitoring = 37'C max. [Core Temp and Speccy agreed with CPUID-HM.] [Speedfan agreed with Asus software.]

This is the issue and it's implications. What temperature is the CPU-fan being controlled by. I suspect the Asus software monitoring at 37'C. I read online, and a forum general opinion is Asus software uses the CPU socket temp, not CPU core temp. The Noctua fan runs from 300RPM, to 1500RPM, yet under load the CPU-fan is maxing at 384RPM. It must think the CPU is still very cool.

Effectively, I think the way the CPU temp is monitored for fan control, may have cost me another CPU cooler. I think if the real core temp was used, the Freezer 7 Pro would have spun faster and been doing a better job.

 

[U6b36ef]

You have many options for fan control, but even 65 is not bad.

Some users want the lowest temperatures and fill all fan slots(just make sure they are somewhat balanced to keep the air moving). Other users will go with the minimum required to keep things within spec.

I get into the low 60's in games on my system and do not worry about it at all. The cpu will be long obsolete before it fails.

With me only using one fan drawing air in I think it's not exactly running optimal. (There are a total of five more slots for fans.) One more in the front or on the bottom will help the air flow through generally I guess.

Air-flow does well already even for the modest one front fan. When I took my last graphics card out of my old pc and put it in this one I dropped 15'C in temps. The old PC was just a stock Acer PC with one exhaust fan.

I think I'm doing OK on temps. Only it's coming to summer (UK) and I'd like to add one more, maybe two. I need a new fan on the CPU as this one in noisy from about half speed up. I want a Noctua for the Noctua cooler but am very put off by this noisy fan I have. I don't hear it at idle but I get a clearly audible whirr every no and again, even with light desktop stuff.

@ Karadjgne, I'm avoiding Asus Fan Expert for fine tuning. It actually raised my CPU temps, being less efficient than standard pre-set. Now I use the pre-set turbo mode. Better than standard pre-set.

 

[U6b36ef]

Noctua just replied to me.

If you recall I mentioned earlier I was talking to them about the noisy fan noise at 800+rpm. However that was in the end of last year.

Yet I wrote to them last night and asked if I could accept their offer of a free replacement fan. They said yes straight away.

That is after-sales service.

 

[nukemaster]

Noctua has very good customer service for sure.

I actually had some NF S12's that had vibration issues(it was early enough that I got them replaced from NCIX instead), But Noctua even gives upgrade kits for new cpu sockets and replacement fan clips i you want to run an extra fan on the D14 or similar.

I have seen some cases that are louder with fans at different speeds as well(so this plays a role for some users.) I like that silverstone has removable fan grilles in the FT03(and some other cases) for that reason(and the stock ones do not make noise on any fan I have tried.).

As for more fans, You can certainly add some, It can not hurt anything(well may add a bit of noise).

My case only has one outlet and one inlet fan(still has vents and a place for another inlet) and my other system has just one 120mm intake(power supply is the exhaust along with some vents). They all run within spec.

 

[U6b36ef]

Noctua has very good customer service for sure.

I actually had some NF F12's that had vibration issues(it was early enough that I got them replaced from NCIX instead), But Noctua even gives upgrade kits for new cpu sockets and replacement fan clips i you want to run an extra fan on the D14 or similar.

As for more fans, You can certainly add some, It can not hurt anything(well may add a bit of noise).

Yeh mine is the NF - F12. I think I read somewhere else it's a fan they discontinued, with a hint that it wasn't brilliant.

I hope that the new fan they send is OK. I think I will put the current CPU fan on the floor of the case, or in the front. If I keep it under 850rpm it will be silent. I could attach it to the motherboard header, because the motherboard stays between about 24-34'C. It won't get pushed there.

If you are interested in my case it's Fractal Design Arc Midi R2. It's main selling point to me was filters over every intake.

Yes I saw that they will upgrade my socket compatibility. I am thinking like you that in the future the 4690 will run out of steam, and I will buy a future gen i5 and a new board. I see no point buying £200-£300 boards and i7. Much cheaper to buy the i5 and a cheap quality (Asus) non-overclocking board, then upgrade when needed. Save a fortune.

 

[nukemaster]

I made a little typeo. Mine was the S12, not F12.

I had my main system in a Define R2 before and the floor fan placement makes extra noise with some fans. You will have to test and see how it works. I do not like bottom intakes too much because of the dust(funny thing is my main system has bottom intake too. Filters are a must for this kind of thing).

 

[U6b36ef]

I just had a peek at the Define R2. Beautiful case.

It looks near identical inside to the Arc Midi 2. The front has no door with the Arc Midi R2, and has a grilled panel. It has a fine foam filter in it, (as does the top).

The floor filter that cover the PSU and floor fan mount, is a fine plastic mesh. I had the PSU out today, coincidentally. I was a little surprised how much very fine stuff had passed through in the last nine months, since building. Not lots, but still surprised. It does a good job. I think I will add a tiny mod, especially if adding a floor fan. I have a Daikin Photocatalytic Air Filter. It has a roll sheets of filters to replace as you use it. I think I will cut one to fit and add it. I can put some more over the side grill. It's an idea for you if you worry of dust from floor fans. You'll just need to source some filters.

Anyway, I am excited that the new fan is coming from Noctua. I hope they send me a good one. The old one getting noisy at 850rpm was a nuisance. It meant even opening apps could cause a clearly audible whirr. Playing games results in lots of whirrs, unless I turn up the fans. I know that's the point of fans. However I felt if the CPU fan was only hitting 850-1000rpm out of a possible 1500rpm, it should be my choice. Meaning my decision which case fan settings to use.

I am also looking forward to putting the old CPU fan on the front or the in the floor.

 

[nukemaster]

Filters are a game of balance. Too much restriction cuts air flow allot, but does catch more dust.

Lucky for my my gaming system does not get that many hours of use so it takes long to get dusty.

 

[Karadjgne]

Oh, 1 thing that seems not to have been mentioned anywhere, pick 1. Asus suite or SpeedFan, my preference is Asus, without a tedious Windows task SpeedFan remains a manual app, but pick just one, or you'll get conflicting fan instructions. Same with monitoring software now that you've tried a few, pick one and run that, so as not to get difference of opinion there. Just make life easier.