Cooling issues with Kotetsu

[doveman]

I've got a Scythe Kotetsu on my i5-4670k overclocked to [email protected].

The case is a Cooler Master XB Evo which is very well ventilated. http://www.coolermaster.com/case/lan-bo ... af-xb-evo/

It idles at around 39-43c with the Scythe CPU fan around 930RPM, the rear exhaust fan at about 900RPM and the front intake 140mm fan at 450RPM.

However as soon as the CPU is loaded (for example, searching files with Agent Ransack which pushes all 4 cores to 100%) the CPU temp jumps to 63c and the CPU fan increases to 1250RPM, which is quite intrusive. The temp settles down after a bit to around 57c and the fan to about 1150RPM (which is still intrusive) but the temps aren't stable and HwInfo shows them constantly fluctuating in a range of around 55-65c. These are the core temps, the CPU temp fluctuates between 55-60c.

Whilst I could adjust the CPU fan profile in the BIOS to keep it inaudible, with the CPU already hitting 63c I think reducing the fan speed would risk the temps getting too high. I also wonder whether the fact that the temps are fluctuating so much suggests I've done a poor job of mounting the Kotetsu and whether I'm likely to be able to reduce the temps and make them more stable under load by re-mounting it? Obviously I don't want to bother doing that unless it's likely to help, as it pretty much means dismantling the PC to remove the motherboard so that I can get to the heatsink bolts.

I've bought some Arctic F12 PWM fans which I've used before and found to have a good noise profile, so I could swap out the Scythe fan for one of those but that's not going to help with the temps and might even see them increase slightly.

[Abula]

Intels Haswell CPUs can take a lot more heat than 63C, my 4770K on prime95 coul easily reach 80C, and now on my camara server where it encondes 24/7 it hits 70C and works fine.

I would start to to worry above 80C, and even then its just more a personal boundary, i believe this CPUs are fine close to 100C.

Either way i would drop the rpms more in favor of a more quiet setup sacrificing temp. Try to check Asus pre establish profiles on the bios for the CPU_FAN / Q_FAN, i believe there is a silent one that its a little less aggressive, and if that doesn't work, install the AI Suite and control them via FanXpert.

[doveman]

Thanks. I knew it wasn't dangerous at the moment, just worried that reducing the fan speed could push it above 70c but if even that is OK then I'll try tweaking it.

I think the BIOS fan profiles let me set the temp/RPM for three different points so I can probably get where I want without installing AI Suite, which was rather buggy last time I tried it (not necessarily the fan part, just in general).

I'm still concerned that the wide fluctuation in temps under load might indicate a problem with the mounting but I know the i5-4670k's heatspreader isn't very good and I'm not about to de-lid it just to improve it, so as long as I can keep the temps within the safe range I won't obsess about it.

[Abula]

I think the BIOS fan profiles let me set the temp/RPM for three different points so I can probably get where I want without installing AI Suite, which was rather buggy last time I tried it (not necessarily the fan part, just in general).

I agree with you, i think AI Suite is too heavy for what we most of us need, specially FanXpert should be a stand a lone app, personally i try to avoid as much as i can software, reason why i like and use MSI in most of my recent builds, although seems asus is doing better fan control on pure bios in this gen.

[xan_user]

If the CPU aint throttling, than there's no issue.

rapid CPU temp changes are normal especially when overclocked.

[CA_Steve]

...and the rapid changes in temp are an indicator of GOOD contact. Poor contact would give fast rise and slow descent. +1 on lowering the fan speed.

[doveman]

Ah thanks guys, that's reassuring to know. I can stop fretting about whether I need to remount the heatsink now

[doveman]

I've tweaked the fans to let the 140mm intake run at full speed (750 RPM) as that's pretty quiet, the exhaust 120mm at 460RPM and the CPU fan at 650RPM.

Under load, the last two increase to about 750RPM and 950RPM respectively, which is a lot quieter than it was before. Especially the CPU fan gets noisy over 1000-1100RPM.
The CPU and core temps max at about 78c now (although the ambient is fairly cold at the moment) but they mostly sit around 71-73c. I've set the fans to go to 100% at 75c to make sure it doesn't hit 80c, so they do become audible then but only briefly before it stabilises. Besides, this was testing with Prime Blend and no game is going to push it so hard, so it should be quiet most of the time now.

I still plan to try swapping the two 120mm fans out for the Artic F12 PWM as I think they might be a bit quieter, so I'll report back when I've done that.

[CA_Steve]

78C for Prime95 sounds pretty good considering you've turned a 84W TDP CPU into a ~150W one.

[plundh]

I've seen some people get such great results with the Kotetsu, but then I've also seen a few people asking if they're doing something wrong since they're getting high temps. Are there some common mistakes people make in mounting it? I felt like my temps were pretty high, so I reseated it with new thermal paste but there's no change. Are these temps what I can expect?

6700K
Kotetsu w/ NB Multiframe M12-2
Silverstone FT-02
3 180mm fans in the bottom, M12-1 on the top

I'm getting 85C and rising duing P95 torture test (Small FFT). I can only run it for 15-30 sec before I get nervous. Should I get a beefier fan? It's quite loud at 1300rpm already, so I was really hoping that wouldn't be necessary.

[quest_for_silence]

Are these temps what I can expect?

What's your vcore? Which thermal paste did you used? Did you tested the Glidestream also?

[plundh]

Are these temps what I can expect?

What's your vcore? Which thermal paste did you used? Did you tested the Glidestream also?

Everything is default. Before I used the paste that came with the cooler, but now I tried som Arctic Silver 5 instead. I didn't run a stress test on the Glidestream, but I think the temps were about the same. I've been running it for awhile like this, but it just now occured to me that I maybe should be able to play a game or do some rendering while staying silent, or is that expecting too much?

[plundh]

Whoa. Good that you asked about the Vcore. As you can see in the screenshot, my Vcore goes up to 1.4v+ during load even though I haven't changed any settings. That seems pretty high? Any idea why it would do that?

[CA_Steve]

Your Asus mobo's s/w is most likely the culprit. Maybe you let it set up an overclock, maybe it did it on it's own Load up the suite and override the settings.

[quest_for_silence]

I didn't run a stress test on the Glidestream, but I think the temps were about the same.

I'd strongly advice to do not suppose, but just test.

That seems pretty high?

Yes it is.

Any idea why it would do that?

Unoptimized BIOS settings, almost surely some "auto OC" feature enabled in UEFI or AiSuite (probably that 4.2Ghz vs stock 4.0GHz in screenshot, which looks suspicious).

[Abula]

Be careful with AI Suite, as others posted sometimes it gets a mind of its own and increses the voltages, specially if you mess around with 5 way optimization.

Have you tried not using AI Suite at all, and just the Bios fan control? it has a section like mini FanXpert called Qfan tunning (if i remember correctly), in there it will also test your fans and give you suggested graphs that you can mess around with them, in my H170 Pro Gaming worked fine on Bios 0403 (from what i remember, as i updated pretty fast) but when i moved toward 0703 it has issues with the fan control, but yours is a Hero, so might work fine, you shoudl try it, and see wihtout AI suite if you still have the vcore issue.

[plundh]

Wow! I made sure the AI tuner was set to Manual in BIOS. It's still running at 4.2 Ghz with Tubo Boost, but on about 1.168v Vcore. Now my temps peak at 65C after 10 minutes of P95, and that's with the fan at 650 rpm! Thanks everyone

On the flip side I'm just now noticing how loud my HD is... gotta do something about that.

(btw It wasn't AI Suite's fault, since I had just installed that yesterday to control fans better. It was the default BIOS setting.)