Apple's new Mac Pro whether you love it or hate it it's journey so far has been an interesting one as a PC guy myself I've got to give a hats off to Apple for making a computer tower that's just so unique and well refined and just overall so different from our typical PC tower in fact there's a lot that the enthusiast PC market can learn from Apple's design but one thing that has stuck with me throughout all of the reviews that I've watched of the 2019 Mac Pro is Apple's approach to airflow and fan speed specifically those three big fans at the front of the case supposedly spin at different speeds and the reason for that is so that each individual fan will be producing a different noise frequency or pitch as opposed to amplifying the noise level at a single pitch
if this is correct that means that you could potentially get practically the same airflow and thermal performance but at much quieter operation and I couldn't help but think if this approach to airflow was so genius and magical as some of the reviews were stating why hasn't the PC community done something similar I mean it's just physics after all Apple doesn't own this kind of style of airflow approach I'm really interested to see whether we can replicate very similar results with a very similar airflow structure as the Mac Pro or perhaps this is just a bit of marketing fluff [Music] so just to recap here the idea here is that if you have multiple fans in your PC
it's better to have them run at different speeds as opposed to the same speed as that way you're able to avoid them amplifying a single noise frequency if this is true we could potentially see better noise performance from our pcs at higher load definitely useful for a workstation or high performance gaming rig on paper it sounds pretty convincing as well we're pretty familiar with what multiple sound sources at the same noise pitch could sound like and so avoiding that amplification is the goal here the thing is though this goes against the traditional way of controlling multiple fans in your system where you'd usually connect them to splitters or a fan controller and then a single PWM or DC fan header on your motherboard that would set them at the same speed to try apples approach on your own system you'd need one fan head up her fan that you'd like to run independently another approach to this stepped fan rpm would be to use your common splitters or a controller but also adapters with resistors built-in to lower the fan speed now before we dive into the testing
I'll first say that I don't know what Apple's exact approach to this airflow strategy is so I am basing this solely just off the very popular reviews that I've seen online talk about this quite consistently so I don't know the exact deltas between the fans that are running here and I don't know what the stepping is but we will dive into that in just a second and we have tested quite a few different configurations the main focus though will be comparing them at the same rpm to one of the fans slightly slower and one of the fans slightly faster for example comparing all fans at 1200 rpm versus one at 801 at 1200 and one at 1400 the test system that I've set up here is in the fractal design defined seven a pretty large mid tower case with a ton of volume inside if you want to build a workstation that's similarly spec to the Mac Pro but on the PC side of the fence this case really is a solid choice it's also got quite a bit of sound dampening material behind the panels excellent if you're looking to build something nice and quiet so three front mounted fans for intake just like the Mac Pro and the only other fan in the system contributing to the noise are on the knock double caller for a thread Ripper 39 70 X but those are spinning at just 500 rpm for all tests
so let's answer the first question of this little experiment and that's that you know do fans actually create a higher pitch the faster that they spin because we know that fans do get louder the faster they go that's pretty obvious but do they necessarily create a higher pitch as well and the answer to this is yes at least for the Noctua nff tools that we're testing here which have a fairly similar sound profile to most static pressure fans that I've tested in the past so along the x-axis of this graph we have the sound frequency so lower pitches to the left and higher pitches to the right and on the y-axis we have the sound level the absolute values here don't really matter seeing as that depends entirely on the gain set by the microphone and the recorder the accurate peak noise level readings can be seen off to the right there so with all the fans spinning at 800 rpm we'll get a quiet low hum at 94 Hertz pumping that up to a thousand rpm raises the frequency to 117 Hertz 1200 rpm generates a peak frequency of 141 hurt and that 1400 RPM we see two peaks at about the same level 164 and a much higher pitch 328 Hertz here's a quick sound test of these before we move on to comparing this to apples steped rpm approach but now let's compare this to the stepped rpm approach where none of the fans are set to the same rpm the theory here is that by doing this they can avoid amplifying the same single sound pitch so here we're comparing 800 rpm on all of the fans to one at 600 one at 801 at 1,000 the conclusion here is that although the slightly faster fan is running at a different pitch it's just plain and simple louder making the stepped rpm configuration the louder and higher pitch option every single time we see this again in our other two tests comparing the pitch and noise levels between fixed and stepped the stepped rpm fan configuration is always louder thanks to that single faster and louder fan and then I thought maybe this just wasn't Apple's approach at all and instead maybe they've just been reducing fan speed altogether and by lower margins so now let's compare 1200 rpm fixed to one at 1000 one at 1100 and one at 1200 and of course that stepped fan rpm configuration is running quieter because the fans overall are running slower this is a no-brainer slower fans are quieter and that's why I didn't plan on testing it in the first place one argument could be that sure the stepped approach is quieter because it's running slightly slower but also because it's running at different frequencies there could be other noise benefits by running slightly different fan RPMs to seeing as the velocity of the air from each fan will be slightly different it might produce a more natural and organic interference between one another but that's descending into an entirely different rabbit hole for now.
I'll leave you with a sound test between them so to wrap things up I'd say that stepped fan rpms may be beneficial for a system with multiple fans that are close to each other but I'd really need to do a lot more testing to see for sure if you have an expertise in aerodynamics I'd love to know your thoughts on this topic down below because I sure do not but taking a step way back I think there's a lot more effective factors that make apples Mac Pro as quiet as it actually is things like a pretty solid power management for the CPU and the pretty beefy GPUs and also a huge heatsink design for both the CPUs and the GPUs that are designed around a slow steady stream of airflow that's something that we are yet to see in the PC market there's also a fairly solid chance that those 0 and W chips even the 28 core are running with a fairly restricted power target and at low voltages as well but without a Mac Pro here I can't really say for sure so maybe this whole fan control situation is a little genius from Apple or maybe it's just a bit of marketing fluff the results here are certainly a bit mixed and I certainly couldn't prove anything revolutionary but I would love to know your thoughts and comments down below as always guys a huge thanks for reading and I'll see you all in the next one
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