[HN Gopher] The Sandia Cooler (2016)
___________________________________________________________________
The Sandia Cooler (2016)
Author : RichardHeart
Score : 70 points
Date : 2021-06-27 14:10 UTC (8 hours ago)
(HTM) web link (ip.sandia.gov)
(TXT) w3m dump (ip.sandia.gov)
| dogma1138 wrote:
| Because it doesn't work https://youtu.be/oCghRn2Zae4
| AussieWog93 wrote:
| The conclusion of the video is that it does work, but the
| performance is not as good as the larger, traditional designs.
| dogma1138 wrote:
| The performance is below low profile traditional coolers like
| the noctua too, it doesn't work as in live up to it's
| promise.
| caconym_ wrote:
| It looks like that design has diverged significantly from the
| Sandia one, probably because they couldn't manage the
| tolerances the Sandia design needs. Given that it's a first
| attempt to bring the concept to market, and that it appears to
| be significantly compromised, I don't think "it doesn't work"
| is a fair characterization of the actual Sandia design.
|
| It might well be completely impractical for the commercial CPU
| cooler market, but it also might be the case that a bit more
| R&D and tooling up could get us a really effective new cooler
| design. Improvements could include [perceived] noise reduction
| as well as better efficacy.
| [deleted]
| tzs wrote:
| It would be interesting to see how that would work if you made
| bigger versions. It was a lot smaller than the others, and I'm
| curious if it would have to be as big as them to match them or
| if it would match them somewhere between its current size and
| their size.
|
| Also, I wonder how much details matter? That certainly looks
| quite a bit different from the Sandia unit. Sandia was claiming
| a large increase in efficiency over other units, and usually
| you only get that kind of increase with either a fundamental
| breakthrough or by using known methods but getting it all
| tweaked and tuned just right. I think Sandia's is the second
| kind.
| knolan wrote:
| I was working on a so called finless cooler around the time this
| first rose to prominence. The idea was that a toroidal vortex
| would give better heat transfer than a lot of fins subject to
| viscous shear.
|
| Our cooler was simply a folded aluminium sheet with a fan placed
| into a hole in the top. We had a somewhat similar couette type
| flow under our motor hub directly over the heat source. We had a
| modest 15% gain over a reference GPU cooler which was almost
| entirely due to the better thermal conductivity of the aluminium
| sheet over the cast heat sink in the reference design.
|
| It turned out that all that matters is cost, nothing else.
| hddherman wrote:
| There was this review done a while ago on a product similar to
| that design, but with some changes made:
| https://youtu.be/oCghRn2Zae4
| lou1306 wrote:
| Since we're talking about CPU coolers, I hope my comment is not
| OT: what's with the recent popularity of tower coolers? They seem
| to pop up a lot in PC build discussions, lately. Am I in some
| echo chamber? Do they provide any obvious advantages over
| "traditional" coolers?
| formerly_proven wrote:
| Top-blowers have been relegated to the low-cost / bundled
| category for ~15 years or so. Tower coolers are much better and
| fit better into the overall airflow of almost all cases.
|
| There are no high-performance top-blowers.
| Zancarius wrote:
| I don't think it's recent. The first tower form factor cooler I
| bought was in 2011 or thereabouts.
|
| Part of the reason I bought that one when I did was because the
| stock cooler wasn't effective and the fan was incredibly loud
| (poor heat dissipation, small fan, high RPM). The tower coolers
| have a larger surface area and ship with larger/slower fans,
| reducing noise. They're probably still popular because they
| work, and they're the only air coolers I buy now.
| RamRodification wrote:
| Without really knowing what I'm talking about: It seems logical
| to me that a tower cooler can be more efficient because of less
| restriction in air flow (air blows straight through + can have
| one fan on each side) and possibly more efficient heat
| transportation through several heat pipes into a generally
| larger surface area.
| Scoundreller wrote:
| This, in theory. A heat pipe is much more effective at moving
| heat than conduction. It's also what laptops use.
|
| Big issue is that heat pipes usually work best upright and
| effectiveness (efficiency?) suffers in other orientations.
| orliesaurus wrote:
| Pretty happy with my Noctua CPU cooler - I don't think it gets
| better than that with performance/noise for the price point (sub
| $100!) - has anyone found better coolers than those? Interested
| because I wanna build another PC soon!
| RamRodification wrote:
| I went with an AIO (all-in-one) water cooler for the first time
| in my latest PC build. Many PC cases today have an area in the
| front or at the top for a radiator and its fans. Mine is in the
| front and has 2x120mm fans that suck air in. I have the same
| amount of fans blowing air out (back+top). All four fans are
| running on very low RPM so it's very quiet.
|
| I really recommend this setup. I think 2x120mm is a sweet-spot
| for price/performance when it comes to radiator size. Smaller
| will require a louder fan. Bigger is obviously better but more
| expensive and might not fit your case.
|
| I used to have a big air cooler. One benefit that I didn't plan
| for is that I'm no longer worried about the stress on the
| motherboard mount from the heavy piece of metal hanging from
| it. Another is less stuff in the way since the bulk of the
| cooler is the radiator and fans off to the side.
| bestham wrote:
| I never understood why one would like to place the radiator
| at the inlet, thus heating the air inside the case. The
| hottest part is still the GPU (even if Intel tries their
| hardest to change that), and by placing the radiator at the
| inlet you are heating the air to cool the gpu with an
| additional 50-150 watt.
| RamRodification wrote:
| I actually placed it up top first, blowing out. But then I
| looked up some tests and recommendations and apparently
| front blowing inward is better. Can't remember the exact
| reasoning but I remember being convinced enough to move the
| whole thing. Temps are great now but I never did a
| comparison.
|
| I assume my way results in better cooling for the CPU
| because the radiator gets fresh air instead of GPU-heated
| air. Maybe it's just about prioritizing CPU over GPU (or
| having more headroom for a few extra degrees on the GPU).
| [deleted]
| formerly_proven wrote:
| AIOs don't seem to me like they're worth it, because most
| CPUs can be cooled by a good tower cooler just fine, and
| those that don't really only thrive on a custom loop instead
| of a 240 mm rad. For gaming - well CPU thermal load tends to
| be modest, so it doesn't matter.
|
| AIOs for GPUs largely don't exist, and that's the component
| I'd watercool first, not the CPU. So we're back to custom
| loop there.
| RamRodification wrote:
| > most CPUs can be cooled by a good tower cooler just fine
|
| Water coolers are definitely still an enthusiast part in my
| opinion. If you're satisfied with "just fine" then no, it's
| probably not worth it. It will give you better cooling per
| decibel but probably worse per dollar, at least on stock
| clocks.
|
| If you want to mess around with overclocking the advantage
| seems to become a bit bigger for AIOs as you crank up fan
| speeds.
| jrockway wrote:
| Every AIO I've ever owned has stopped working not too far
| into its life. I remember being shocked and dismayed the
| first time I had one fail, and simply upset when the second
| one failed. After the second failure, I bought a Noctua
| NH-D15S and that heatsink has happily survived 4 builds.
| (Only getting replaced after I switched to Threadripper,
| which required a different Noctua heatsink. But don't
| worry, the NH-D15S still lives on in a friend's PC.)
|
| In my opinion, there are two viable cooling solutions: a
| high-quality heatsink and fan, or a custom water loop. AIOs
| just don't have the performance to make the failure rate
| acceptable.
| chrisseaton wrote:
| But they don't fit into the space requirements this cooler is
| designed against.
| zinekeller wrote:
| ThermalTake has actually released one based on the Sandia design
| (and Cooler Master flirted with this one), but it's not really
| living on its promises. It works, but there's a lot of non-Sandia
| designs with comparable size that works as good or even better
| than ThermalTake's Sandia-like design.
|
| Reviews:
|
| Gamers Nexus: https://www.youtube.com/watch?v=u2tCnjb6lp8
| (video), https://www.gamersnexus.net/hwreviews/2806-thermaltake-
| engin... (text)
|
| Quote from Steve: "Ultimately, the Engine 27 isn't a bad cooler -
| it performs about the same as similarly sized products, so it's
| not some crime against humanity. That said, it's priced
| significantly out of its performance bracket, and the high-
| pitched whine at max RPM can get a bit irritating. You'd want to
| run this at a lower RPM to account for that."
|
| Linus Tech Tips: https://www.youtube.com/watch?v=oCghRn2Zae4
|
| Quote from Linus: "The Thermaltake Engine 27 gets my "Better than
| Nothing" award for working better than I expected given its size,
| making it a great option if you don't have anything else that
| will fit."
| Nursie wrote:
| I have one of those I used in an SFF build, and I like it -
| it's pretty as well as low-profile.
|
| But it's no revolution, and only rated up to 70W.
|
| (UK Product page - https://uk.thermaltake.com/engine-27.html)
| Causality1 wrote:
| I'm not clear on how high speed is supposed to eliminate fouling.
| Sure, particles are less likely to adhere but you're also
| increasing the number of particles.
| bestham wrote:
| As the speed increases, the percentage of particles that stick
| declines quicker than the percentage increase in volume of air
| (and thus particles that may stick). How can you remove dust
| from a fan? One way is to increase the flow of air to "blow"
| away the dust. Same principle here.
| Causality1 wrote:
| Just from observing dusty PC fans being turned up to higher
| speeds, I think the effectiveness would be limited. Most of
| the cleaning is accomplished from having air flow impact the
| surface at a different angle than usual, and at a much higher
| static pressure.
| h2odragon wrote:
| The rotating mass of the heat sink would need an enclosure for
| safety reasons, negating most of the airflow advantages.
| "Transfer heat through an axle" sounds like one of those "draw
| the rest of the owl" steps too; no idea how that's supposed to
| work.
|
| *edit: Maybe a hydraulic motor where the fluid is turning a big
| impeller? Torque converter with an open side, kinda thing...
| amelius wrote:
| Perhaps the CPU is rotating too? Wait, perhaps I should patent
| this idea first.
| Y_Y wrote:
| The amazing part of this is that each individual core makes
| contact with each region of the (obviously stationary) memory
| drum once per revolution, providing dynamic cache adjacency.
| KMag wrote:
| Right. High thermal gradients through ball bearings or roller
| bearings are tricky, and you don't get much contact area for
| thermal conduction in the bearing (meaning most bearing
| applications need to be mindful of cooling). (Pro tip from MIT
| 2.72: make sure to position bearings such that thermal stress
| from the shaft undergoing more thermal expansion than the rest
| of the machine doesn't jam the bearings.)
|
| I guess you'd want a bearing with sodium-potassium alloy
| (hazmat!) or mercury (hazmat!) or something. Or... make the
| casing for the shaft into a heat pipe with ammonia or alcohol
| vapor.
| icegreentea2 wrote:
| As described by the lab, the Sandia cooler predominantly
| transfers heat across an air-gap (maintained via self-generated
| fluid bearing) between the base plate and rotating impeller.
|
| As described, they claim that if they can maintain the air-gap
| to 10um, then they get a net win since the specific (per
| surface area) thermal resistance is sufficiently low (due to
| only being 10um), and the transfer surface area is
| comparatively enormous. Nevertheless, the air-gap still forms
| the dominant component of their overall thermal resistance.
|
| Reading through their posted development report [0], it's
| apparent that they were having trouble hitting that 10um target
| with their designs.
|
| Not exactly a surprise that this is the most difficult part.
| Not surprising that the "commercialized versions" (see other
| posts) don't use this mechanism.
|
| [0]
| https://ip.sandia.gov/techpdfs/Development%20of%20Sandia%20C...
| drudu wrote:
| A linked video claims that the commercial version attempts to
| transfer heat from one rotating metal surface to another (the
| the part that connects to the CPU and the bottom of the
| spinning thingy) separated by an extremely thin layer of air.
| This is "supposed to" transfer heat as if the metal is touching
| but "doesn't see to work very well in practice"
| salawat wrote:
| Immediately popping into my mind: what rotates it to facilitate
| pumping, and also, if the top rotates, how is the thermal
| transmission between the baseplate and the rotating element being
| facilitated? It's either have to be through the axle, or you'd
| need some sort of lubricious, yet thermally conductive compound
| for the rotating element to flow through, which, not gonna lie,
| sounds pretty magic to me.
|
| Also, I'd need to look into the mechanics of this cylindrical
| impeller bit more. Boundary layers don't go away magically in
| laminar flow conditions. They might shrink, but they don't
| disappear. I also look at the center of their prototype, and all
| I see is a debris accumulation point that will become more and
| more obstructed over time in high debris concentration air. There
| isn't that much preventing dust build up on the top too, which I
| think may contribute to further build up.
|
| Noise, no comment, except I know that if you've got spinning
| parts you've got harmonics and vibration, audible or not.
|
| The burning question for me though, is how does it pan out in
| test designs. If it keeps stuff cooler under operating
| conditions, with better MTBF than what we're traditionally using,
| screw it, it's better.
|
| Especially since in a sense you're combining two distinct parts
| into a single one, which would in theory simplify fabrication.
| However, that looks to be all metal, so it may not be cheaper
| than a fan static heat sink combo.
|
| Be a fun thing to test and put through it's paces to be sure.
| chrisseaton wrote:
| > what rotates it to facilitate pumping
|
| A motor.
|
| > how is the thermal transmission between the baseplate and the
| rotating element being facilitated
|
| Through the micro-meter thick air bearing.
___________________________________________________________________
(page generated 2021-06-27 23:00 UTC)