Finally! Some serious third-party data on fans.
View and discuss. Help them with suggestions on how to present data as stated in the “Why This Test is First” chapter.
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What would really help is an explainer animation explaining the relationship between airflow, obstruction, pressure drop, and how the machine can simulate resistance to a precise measure with it’s counterblower.
Visual learning helps much more than trying to verbally explain everything.
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I tend to learn better visually, as well. I’ll send them a link to this forum post so that they can cite properly.
Edit: Sent an e-mail to [email protected]. Perhaps @wendell can make sure that they know about it in case forum members only post ideas here and not on YouTube (or if that e-mail is no longer in use, rarely checked or has strict spam filters that don’t allow links).
Yeah, there’s also the fact I’ve tried to email about trying to get work at GN before and that must have flagged my email for spam. My uncle lives in Cary and he’s been trying to reach Steve too on my behalf.
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I tried to get RAM overclocking advice a few years back because there wasn’t a whole lot to go by and I trust them (and for that specific system, I wanted to validate against their testing methodology). I figure that was lost in the swamp of things that they definitely receive daily.
They had a specific job inquiry e-mail if I’m not mistaken, but this was a couple of years ago before the new website and when they were actively hiring, so I don’t know.
I’ve met Steve in person at LTX but because I didn’t have a solid plan for getting hired by him at the time I only gave advice. When my Uncle visited me from NC recently I wanted to use that to have him approach on my behalf. It would involve moving from Canada to NC but my Uncle has a house in the same city as GN HQ.
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I sincerely hope that this reaches Steve, then. 
Anecdotally, I never bothered applying to work for them because I only have personal experience and no collegiate degrees to back up what I do know.
Yeah, I was in the same college class as Brandon and Edzel of LTT. They went on to be successful, I was left behind because I couldn’t socially communicate due to my autism.
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I have severe social anxiety issues among other things (hence why I never completed college), so I fully understand. My mother swears that I’m on the spectrum, but it’s never been diagnosed. You’re not alone, though.
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Most of them don’t either, afaik. I wouldn’t let that alone stop you from trying. I’m guessing the lack of response is more to do with GN just not being in hiring mode. They have a LOT of new names popping up, I’m guessing they filled all their openings they were advertising a while back.
I believe I remember Steve casually dropping mention of “hundreds” of emails a day in a video recently. If that’s the case, I’m not surprised an unsolicited general inquiry, employment or otherwise, went unacknowledged.
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Precisely.
When they were actively hiring, though (seems like 4 years ago?), it was very professional, asking for writing experience and schooling in very specific subjects. I think that was a turn off for a lot of people, especially hyper-enthusiasts that only have personal experience and not the typical industry blanket asking of 2-5 years proven experience.
I would have had to uproot and move near them, as well, which isn’t a small feat, same as @FurryJackman, but I don’t have family around there.
Just saw this (I had unsubscribed to Jay for a while but missed the silly stuff) and Steve says that they want people that love to learn. ~waves hand~ 
If he ever sees this, where can @FurryJackman and I apply (or anyone else for that matter)?
I forgot to watch it. so this topic is a good reminder for me to take a look. I’m a mechanical engineer with some experience in the physics behind this.
First off, the machine is really cool and allows for testing and information that just hasn’t been available yet.
- I really don’t like them referring to it as “porosity” the size of the holes and the edge finish is a large factor on how the air interacts with the plate. The way air moves especially on the suction side of a fan is kind of voodoo magic. I’ve worked with engineers trying to do CFD simulations and it is incredibly hard to do well.
- a Caveat with this kind of testing is that it will never be 100%, you can’t simulate the conditions in a case, temperature of air and exact inlet and outlet conditions but you can get close. In the end this is just a theoretical benchmark to make better sense of the reality.
- It’s awful they are using mmH2o together with cubic feet per minute as units stick to metric or imperial, not a mix of both. i like m3/h together with pascal. but 1 mmh2o is the same as 10 pascal (technically 9.81 Pa)
- They didn’t really explain well what system resistance and fan curve’s are. and how they interact. This would also allow some theoretical calculations to validate results. The e-mails they show are correct but they don’t seem to understand it yet. If you want to explain how a system pressure drop works, its better to leave laminar flow out of it.
- They tested at 100% and 60% PWM which is cool, but they should have also compared rotational speed and to make it more real world scenario, they should have added some counter pressure, which i’m not sure was the case here.
- Obstructions on the inlet of the fan are incredibly variable, even just changing the distance 10mm can change the results drastically together with the exact form of the obstruction. Would have been nice to test a little further or a little closer (as that happens in all kinds of cases) Their test where they just look at pressure drop from the different “porosity” is really invalid when talking about placing it at the intake of a fan.
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You’re not a real engineer if you don’t mix absurd units. There’s one in my field of “kilowatt per foot”. There’s another one (that I don’t claim or like) that uses the prefix “micro-micro” (pico) and “/100cm^2” - per hundred cm squared, which, incidentally, is described as a 4"x4" area.
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Not going to argue with either of you. I never took any advanced math in school (not because I couldn’t, mental health didn’t mean anything when I was growing up), but maybe @nutral meant as an industry standard? mmH2O is an ADVERTISING standard and not a proper way of depicting it?
I don’t feel that any of your concerns are invalid, but specifically when talking about ‘porosity’ I believe Steve is using the term correctly:
“the ratio of the volume of interstices of a material to the volume of its mass”
It’s a measure of how much open space exists in a planed surface to allow fluid motion through. It’s a basic measuring that lacks the dynamics of measuring the size, shape, or curvature of those holes. It does not claim to be an accurate model for CFD or even a facsimile of performance ‘in a real PC case’. But then again, Steve is not an engineer with a background in Mathematical Modeling or Numerical Analysis.
I agree with his approach of ‘starting somewhere’, and keeping it simple and consistent. A machine like this could take many, many hours to learn, and he has to justify that enormous R&D cost at a tiny organization somehow.
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Its more probably an opinion of mine, because i didn’t really research it. Everyone is always learning and improving. I do feel GN holds everyone to such high standards that it kind of stifles that learning process. Even in the video scared of getting it wrong they just put the e-mail from the engineer in the video.
Do understand why, because the internet seems so cruel and its impossible to cover every part.
What i would do with the machine is just test fans under different conditions and check that with formula’s like for example affinity laws and manufacturer stats. testing the fan under different RPM’s, and testing that against an open outlet/inlet and testing it against a fixed counter pressure. If it all works correctly you should get roughly power of 2 factor on for example resistance under flow or pressure as you change the speed of the fan.
The SRC orifice test on the panel porosity seems to have a really high pressure or maybe the unit is wrong? it says mmaq which i think is mm aqua. a noctua 12cm casefan has a pressure of about 2mm aqua. so that means the fan would have almost no flow through the 63% porosity one.
Seems a bit strong to say this? Am I not an engineer because I don’t mix units in reporting? Sure there are fields where weird units are mixed (even then when calculations are required you do go to 1 system). But for this one there are perfectly adequate units for both.
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This is part of why I started this thread; scientific discussion.
I personally prefer long form, but I don’t work anymore, so I have time for it. GN is, at the end of the day, a business that needs to cater to the majority of its audience to survive (like ANY YouTube channel). They’re also a small team (relatively), so everything is spread pretty thin. I think the only reason Steve is the face of the entire channel (other than starting it) is because the rest of the team doesn’t necessarily want to be on camera, which is understandable. We don’t see a whole lot from the L1 crew besides Wendell outside of Links with Friends. I want to see it. I’d love to see moderators’ projects in hours long video formats.
that was a joke, riffing on the fact that mixed or otherwise odd units are very, very common in the real world.
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mmH₂O + CFM’s the most common units combination for 80, 92, 120, 140 mm, and similar fan specifications. It’s also used in a lot of the datasheets I’m thinking of offhand.
He is. The standard term with punched plate is open area but percent porosity and percent open area are the same thing.
That GN doesn’t. Neither does HWBusters, who’ve been running an LW-9266 for a while now.
Noise normalization is the usual basis of comparison but it can’t be measured on Longwin’s AMCA 210 series because of the compressor and backpressure fan. See QuasarZone and HWCooling’s test fixtures for noise-normalization capable setups with semi-realistic system effects.
The front panels are the resistances under test so lack of counterpressure’s ok. While a more realistic config would include case loading, per AMCA 210’s duct callouts, that’s well beyond GN’s current skillset. Their machine’s not big enough for (m)ATX cases or useful direct tests on SFF anyways. Other problem there is where the air goes in the case matters, which isn’t something in scope to AMCA 210 fixtures.
I don’t disagree with the point about RPM normalization but, as fan curves are specified in % PWM rather not RPM and a lot of the 120 and 140 mm fans used don’t hold an RPM very well, it’s not all that relevant to the use case. Not that 60 and 100% PWM are great choices either as typical (custom) fan curves run in the 0-50% range.
It’s valid. As Steve points out in the begining, the intake clearance is representative of better designed cases. Yeah, the dataset’d be more useful for design analysis if it was a factorial set of measurements over open area and spacing. But then you’d have to listen through Steve rambling for twice as long. Life is full of tradeoffs.
Yes, something’s off there.
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