[SOLVED] what am i doing wrong with new fans?

[krissyneillie1]

hello, so ive just installed 2 140 Noctua NF-A14 PWM fans on the front of my meshify c and my idle temps are at 55c for the cpu (ryzen 2600x), im waiting on 2 120 Noctua NF-F12 PWM for exhaust so at the moment its the stock 3 pin fractal fans, im trying to setup a fan curve on the bios, b450 tomahawk but i have no idea what i should be setting them to, ive set the two fronts to PWM and selected smart mode, thats the only way a fan curve can be set, nothing i seem to do will bring the cpu idle temp to around 40, which it was sitting at with the old 120 3 pin fans on the front, im also waiting on a mugen 5 cpu cooler to replace the wraith spire, i would of thought i would see some improvements at the moment with the new noctuas installed on the front, ive tried and tried with google and theres no solid info on a decent fan curve or what it should look like on the bios, i know every system is different but i just cant figure out what values i should be inputting to see some improvements, i dont even want to game with it yet as i fear temps will rocket

 

[Darkbreeze]

https://forum-en.msi.com/index.php?topic=309929.0

 

[krissyneillie1]

Thanks for that link i had a look and partially helped, I've set a fan curve for the front fans
30c 20%
40c 50%
50c 80%
60c 100%

Does that sound about right?

I now have the rear fans and have set them to the same for now as a baseline but I suspect the rears will need to be altered to allow the heat to be exhausted, I'm just not sure what those exhaust values should be

 

[Darkbreeze]

Personally, like I said in the other thread , I like 20% up to about 40°C, because some systems may idle up to that temperature and you don't want or need high fan speed at idle, plus idle temps don't much matter unless you are idling at higher than 40°C anyways. Then for the next point I'd go with about 35% at 50°C, then 50% at about 60°C and then 100% at about 75°C.

All that matters, really, is that you keep the true idle temp below 40 degrees, and the maximum temp below 80 degrees. Anything else is a matter of preference. I prefer quiet while still getting temperatures that mostly stay below 65°C except when I'm doing something VERY demanding, in which case I can tolerate a little noise because I expect that but I still need to hear myself think and with Noctua fans, even at 100% fan operation, I can.

I would set your exhaust fans with a slightly higher curve than your intake fans, since they are smaller and move less air. I tend to use 140mm fans all the way around, but a lot of cases don't support a 140mm fan in the rear exhaust location so that's not always an option. You have to work with what you have. You want a balance of exhaust and intake, so a slightly faster RPM on the exhaust fans that are smaller will help to create an equal pressure differential in the case. That offers a good mix of cooling performance with at least SOME suppression of dust intake. Positive pressure helps keep dust out, negative pressure increases cooling performance and makes it easier on the intake fans, especially if they are not a high static pressure model. Yours however have good static pressure so it's fine either way you prefer.

 

[krissyneillie1]

Thanks you've been more than helpful, I'll have a play around with the curves with your recommendations and go from there, although my idle is mid to high forties with what I have setup at the moment, bear in mind the mugen 5 isn't fitted yet, running wraith spire so I can't be 100% on idle temp, once that's here the fan setup is done

 

[Darkbreeze]

Yes, I wouldn't worry terribly about what the CPU is going to do when setting the case fan curves. Technically you should probably set those to run off the motherboard or VRM sensors anyhow, in the advanced fan settings if your board gives the option, rather than for them to run off the CPU temp sensors.

The CPU temp sensors are VERY reactive, as core temps can rise and fall in milliseconds, while the motherboard temps tend to take much longer to go up or down. Case fans responding to CPU temps will constantly be raising and falling, which is annoying. I'd look into whether those settings are changeable on your board or not. Probably they are.

For CPU, obviously you want THAT to use the CPU sensors, and is usually NOT changeable. Either way will work though and I'd worry about it after you get the new cooler installed.

 

[krissyneillie1]

My temperature source options are CPU, System, MOS and Chipset

 

[Darkbreeze]

So, for the case fans you probably want to choose "System". For the CPU, obviously, CPU. Sometimes it might be desirable to leave the case fans on CPU. You will have to experiment and see what works best for you AND what you can tolerate as far as noise. CPU will case case fans to FREQUENTLY ramp up and down. System will be a much more gradual process and usually is the preferred option. That or chipset. I guess it depends on what they mean by "System" on that particular board and you can find that out on the MSI forums most likely. I'm sure it's been discussed before for that board model.

 

[krissyneillie1]

So, for the case fans you probably want to choose "System". For the CPU, obviously, CPU. Sometimes it might be desirable to leave the case fans on CPU. You will have to experiment and see what works best for you AND what you can tolerate as far as noise. CPU will case case fans to FREQUENTLY ramp up and down. System will be a much more gradual process and usually is the preferred option. That or chipset. I guess it depends on what they mean by "System" on that particular board and you can find that out on the MSI forums most likely. I'm sure it's been discussed before for that board model.

Hi Darkbreeze, so the mugen 5 is now in and temps are pretty cool, seeing mid 40s under load, I'm happy with that, gpu tends to run at about 70,nothing I can really do I don't think other than run afterburner, I believe that's just normal temps for that card, either way I'm happy the cpu is cooler and the case is also cool, your help has been fantastic

 

[Darkbreeze]

70 degrees under load for the GPU is fine. Totally normal. Glad it all worked out man. Nice.