Airflow has lots of involved variables. And of course there are exceptions to every rule.As mentioned, it depends on the nature of the restriction.
Through a Rad, for example, you get a lot of turbulence and half the noise is the airflow bouncing around and collectively reverberating off different surfaces. HDD cages tend to act like baffles in an exhaust silencer, killing the airflow and spoiling all that lovely spread configuration.
I often find the restrictions slow AF fans down a touch, which keeps the noise down a bit, but they still perform... whereas SPs force the air - This gets noisy, so you turn them down, which drops performance, which heats your system, yadda yadda.
If you're having to turn it down because it's 'too noisy', what's the point? You're robbing all the advantages, though I'd suspect a bad choice of fan/mount if it's that problematic... They should all be fine below 1,000rpm.
But this is why some people rip out the meshes and filters - Better performance at lower noise without having to change fans.
SP forces air through restrictions, partly because it's focused flow, but they're designed to just get through that short distance where its restricted.
AF shifts a lot of air, but still has reasonable pressure too.
Case in point: You put SP fans on my side intakes, where there's almost no restriction at all, you will force air through but achieve nothing. You can barely feel it 6" away. You put AFs there, you will blast loads of air in at a decent spread and the whole Mobo will cool very nicely.
Most fans are dead quiet from just under 1,000rpm. It's how they perform at that point and below that matters for daily use.
It's more that the system is being overclocked or otherwise suddenly stressed that causes it. Curve it up all you like, but going from 5% to 80% load will result in spin-ups as the fan meets whatever levels you set it to.
I prefer constant noise (as do the people I'd normally disturb), which is why I retain manual control.
No, although it depends on what you need and want.
If you have massively capable fans, I'd reckon you bought them because you needed them.
As is, I get flappy when my system components go above 25ºC, but I came from having a build where they'd near-idle at 44... Maybe I'm just OCD about it now, but I still require things to be as cool as possible, which is why I have decent fans.
Err... yes it does!!
Well, it does for bikes, anyway. Not sure about cars, but given how I see people drive them I assumed it is mandatory...
I actually get better mpg if I go everywhere fast... I get 28-32 normally, but over 50 if I'm doing (ahem) speeds...
Restrictions don't "slow the airflow" .. they reduce the airflow. That is the reason to have fans that can overcome the restritions.
As for "turning it down because it too noisy", then why do you have a controller at all? Why do notebooks, CPU coolers, GPU coolers etc have automatic fan speed controls that vary the air speed to keep things cool? Answer is it's logical way of doing things. Keeps system quiet 90% of the time and the few time we work them under extreme load the fans speed up and keep things for burning up.
SP forces air through because it can .. AF does not because it can't. Put both on a radiator and you will see a big difference.
Fans can and are designed to channel or spread air as needed. It is not in any way a function of SP or AF.
Airflow needed to keep things cool is directly related to amount of heat that needs to be removed. At normal workload there is no reason with proper adjustments for an automatic control to cause fans to "Whizz" up and down .. unless the cooler the fans are on is too close to it's cooling limits, aka not up to the task.
Yes, you are definitely OCD.
But so am I.
I'll stick with fans that can move more air if needed. As for PWM fan speed cycling, they can be manually controlled just like variable voltage fans. PWM is just another way of controlling rpm .. in fact a more efficient and better way.
I guess our definitions of quiet are different. At 300-600rpm most are dead quiet / silent, but I have never had a 1000rpm fan that was dead quiet / silent. Not even in open air use.
Err, no it doesn't!
Although I will admit it can be tempting at times. With few exceptions I've always and vehicles and bikes with way more performance than I used on the street .. and my driving record is clean.
