Have you ever had thermal issues with your computer and thought, 'Wow, if only I could get a bigger fan, I might

be able to put my side panel back on'? Well, if that's the case, we've got the fan for

you. And uh, this thing is powerful. [Music] Synergy allows you to share your mouse and keyboard between multiple computers

at once. Check it out now at the link in the video description. So listen, right here is the Delta

PF120912XHE—uh, let's just call it the 'Blowiematron.' And at $55, it is the most

expensive blower I've ever gotten. I mean, this thing is almost four times the cost of even a high-quality

normal consumer fan. So, can it possibly deliver four times the performance? Well, funny you should ask; try more like

seven times the performance! Ramping up to a whopping 11,500 rotations per minute, the Blowiematron can push a

staggering 90 liters of air every second. But how would we actually demonstrate what that means in real

world terms? This thing not only spins faster than the engine of my Civic, it probably has more torque, too.

If you were to get your finger in this thing… well, to put it lightly, you're gonna have a bad time.

Oh! [Music] Oh, we finally stopped it! Jammed full of carrots! So then, with all of that blowing

power, we started to wonder, 'Well, what are the real-world applications?' So here's one: if you're really crunched

for space in your case, at 37 millimeters tall, the super tiny Noctua NH-L9i

is about as small form factor as you can get for a heatsink. But, of course, that comes with some trade-offs.

mainly that you aren't supposed to use it on a high TDP CPU, that is the thermal output CPU, but there's the way it

suggests in the manual and then there's the Linus Tech Tips way. So, can this heatsink cope with a fully clocked Core

i7 7700k? Well, actually it's a surprisingly resilient little bastard and was able to keep our 7700k

running at full turbo speed under synthetic load, though it wasn't exactly comfortable at a maximum of 97 degrees Celsius.

Fortunately, though, our CPU won't have to run hot for long since good old blowing matron is coming to the rescue.

But how much of a difference does a seven-times increase in airflow make for real-world cooling? Well, Alex here is a

great big cooling nerd, so the first thing we're going to do is look at it from a theoretical standpoint.

What is it that makes a heatsink remove heat from a CPU, and why does a bigger, better fan cool it more?

To put it simply, there are three things that affect how much heat you can remove from your processor: the surface area that is responsible for

cooling; the heat transfer coefficient of the process; and the temperature difference between the CPU and the surrounding air. Now, it's intuitive that

increasing the amount of air over a heatsink will make it cooler. Think about putting your hand out of the window of a

car; you go faster, you cool more. But how much can upping the airflow help your cooling? So, to figure out how big of

a difference this is going to make, we have to calculate the convective heat transfer coefficient of air, or how much

heat air can take away from an object, which is approximately equal to this formula, where h is the heat transfer

coefficient and v is the velocity of the air. So we know the knock to a fan pushes air at about

One meter per second, and plugging that into the formula gives us an h value of 19.5. While blowing the metronome pushes air at

3.6 meters per second, giving us an h value of 25.8. But Linus, it's pushing the air 3.6 times

faster. Why does it only make a 25-degree difference to cooling? Well, you see, I was doing math the other day, and this

frigging square root over the velocity kept kicking my ass. You get diminishing returns the faster the air moves.

So, bringing it back to the real world then, can this be confirmed with the blowing metronome? Well, with it strapped to

our NH-L9i under full load in AIDA64, the CPU maxed out at 73 degrees Celsius.

Leaving us lots of room for overclocking, by the way. This also amounted to about 30 percent

cooler than the stock fan, close to our expected temperature reduction of 25 degrees. And really, the LMG thermodynamics and

precision pizza-heating department considers anything within an order of magnitude a compelling victory. Of course, that compromised some of the

space savings with our heatsink, leading us then to another question. This video really turned into kind of a

voyage of discovery. What's better: having a cooling solution that's three-quarters fins or three-quarters fan? Well, we

tested it, and in this situation the fan actually still wins in cooling performance per height, although it isn't all hunky-dory. Strap

one of these guys to your heatsink, you're off to the races with a chilly CPU. First of all, there is power delivery.

That stock fan draws 0.14 amps at full load. The blowing metronome, on

the other hand... well, you probably don't want to attach this thing to a fan header on your motherboard, since it

draws a whopping four and a half amps at full load, which is nearly enough to overwhelm

this bench power supply. And of course, there's also the noise the Noctua fan puts out—24 decibels maximum,

which is quieter than someone whispering in a library. Compare that to the 75 decibels of the

Delta, which is more comparable to an alarm clock. Synergy is a software download that solves the problem once and for all of

having two keyboards and two mice on your desk. If you have more than one PC, it lets you share a single mouse and

keyboard between two or even more computers seamlessly. So you'll no longer get confused about which one is connected to

which. They offer a basic and pro option with a one-time payment for lifetime access, and the features include

clipboard sharing between the computers, dragging and dropping files between the computers, the ability to set up hotkeys,

and more. And the best thing is that Synergy is cross-platform—whoa! PC, Mac, and Linux. So use our link in the video description

to get up to 50% off Synergy today. So thanks for watching, guys. If you disliked this video, well, you must be in

the, uh, banana protection league or whatever the case may be, because we ravaged that thing! But if you liked

it, hit that like button, get subscribed, maybe consider checking out where to buy the stuff we featured at the link in the

video description. And also down there, we've got our merch store, which has cool shirts like this one—banana and carrot

chunks not included—as well as our community forum, which you should totally join.

7X YOUR COOLING – 11 THOUSAND RPM FAN

Linus Tech Tips is a passionate team of "professionally curious" experts in consumer technology and video production who aim to educate and entertain.
