cpu_opt or cpu_fan ?

gib73 · 2 Oct 2015 at 20:02

Just built new PC using i7 6700k and Asus viii ranger.

Using air cooling, a Noctua nh-u14s, and wondering using the cpu_opt or cpu_fan connector on the motherboard?

Glanza · 2 Oct 2015 at 20:19

cpu_fan is the default however both will run the same speed you set on cpu.

gib73 · 2 Oct 2015 at 22:43

What is the difference ?

pete910 · 2 Oct 2015 at 23:07

its for a optional/extra fans/pump

I have a ek d5 pump on the cpu_opt header my sabertooth

gib73 · 3 Oct 2015 at 20:58

Thanks for the replies.

Have another query.

Every time I run a program I can hear the CPU fan speeding up. Quite annoying and I remember somebody else on the forum reporting the same problem with their new build but cannot find the post.

megatron · 4 Oct 2015 at 05:48

Choose a program to display your CPU temp, fan speed, CPU % utilization over time. I would choose Gigabyte SIV but since your with Asus u need to use the Asus equivalent or MSI afterburner. Once you have the required info then u can look at any possible tweaks you can make like fan curve (from within bios or software). It would be ideal to adjust via bios but in my case I use speed fan meaning it runs 100% of the time to control fan speeds (I've given up on Gigabyte's SIV, the lack of flexibility was the last straw, and the bios is not as tweakable with regards to fan speed as others I've seen with a graph control in the UEFI part).

tl;dr more info needed.

gib73 · 4 Oct 2015 at 21:05

Thanks for the reply.

I'll install the Asus software to control the fan and see how I get on.

Danny75 · 5 Oct 2015 at 05:44

The Asus BIOS is really very good for fan control. I wouldn't bother installing the software (which can cause conflicts some of the time).

The trick in your case would be to raise the minimum RPM to a level you're happy with, so the fan PWM gradient and thus the change in pitch as it speeds up, is not so pronounced. You can also lower the maximum RPM slightly if you're unhappy with how it sounds at 100%, or (preferably) increase the max temp ceiling slightly for when it does run at 100%.

Just have to find the location for the fan control in your BIOS.

mods1965 · 5 Oct 2015 at 06:43

I use FanXpert on my Gene VII to control my fans/rads and pump. I just set profiles for each item to keep the noise down and hit a reasonable temp for my loop. I work on 60% of fan speed for max temp and my DDC pump at approx 40%. It works well for me and I have never had any conflicts with other software. I never go 100% for anything as the pump and fans become too noisy.