<div dir="ltr"><div dir="ltr"><div dir="ltr"><div>Prentice, the website refers to Open Compute racks. "... technology has been designed to fit into standard Open Compute racks".</div><div>So yep, 19 inch racks are not being targeted here. But OCP is pretty widespread.</div><div>I would really like to find out if they can retrofit these to existing kit. I suspect though that you need servers engineered to fit onto their heatsinks.</div><div><span style="text-align:left;color:rgb(255,255,255);text-transform:none;text-indent:0px;letter-spacing:0px;font-family:myriad-pro;font-size:22px;font-style:normal;font-variant:normal;font-weight:400;text-decoration:none;word-spacing:0px;display:inline;white-space:pre-wrap;word-wrap:break-word;float:none;background-color:transparent"><span style="text-align:left;color:rgb(255,255,255);text-transform:none;text-indent:0px;letter-spacing:0px;font-family:myriad-pro;font-size:22px;font-style:normal;font-variant:normal;font-weight:400;text-decoration:none;word-spacing:0px;display:inline;white-space:pre-wrap;word-wrap:break-word;float:none;background-color:transparent">orced Physics cooling technology has been designed to fit into Standard Open Compute Racks. </span>orced Physics cooling technology has been designed to fit into Standard Open Compute Racks. </span></div><div><b></b><i></i><u></u><sub></sub><sup></sup><strike></strike><br></div></div></div></div><br><div class="gmail_quote"><div class="gmail_attr" dir="ltr">On Mon, 28 Jan 2019 at 16:48, Prentice Bisbal via Beowulf <<a href="mailto:beowulf@beowulf.org">beowulf@beowulf.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid">
<div bgcolor="#FFFFFF">
<p>So I was thinking about this over the weekend (because I
apparently have nothing better to do with my time), and I
definitely think this is a non-starter due to the massive change
in server hardware layout to accommodate this thing. Yes, blades,
and twin form factor servers already required that, and they're
common form factors, but those form factors were just a matter of
shrinking or changing the layout of the motherboard but still look
like "traditional" layouts to the untrained eye, and they were
still designed with typical front-to-back air cooling in mind. I
feel like re-arranging the layout of components to accomodate this
thing is a just more of a change than the market will accept. <br>
</p>
<p>Just my 2 cents. <br>
</p>
<pre class="gmail-m_-4339801130891775252moz-signature" cols="72">Prentice </pre>
<div class="gmail-m_-4339801130891775252moz-cite-prefix">On 1/25/19 3:56 PM, Prentice Bisbal
wrote:<br>
</div>
<blockquote type="cite">
<p>Eric, <br>
</p>
<p>I was suspecting that might be the case, but the explanations
in the other articles were way too vague to be sure of that. The
NextPlatform provided much better pictures. If that's the case,
this thing operates like a direct-expansion (DX) refrigeration
system, where the refrigerant is air and does not change state
from liquid to gas, like a typical DX refrigeration system, and
the induced-draft fan provides the shaft work, and those tiny
channels that allegedly line up the molecules act as many tiny
offices for the throttling process. Based on the pictures in the
Next Platform article, here is a crude drawing of cross-section
of one of these devices that I drew in Google Draw. It should
help you understand what's going inside this thing: <br>
</p>
<p><a class="gmail-m_-4339801130891775252moz-txt-link-freetext" href="https://docs.google.com/document/d/1UK94PxVlQtVSb2ns5TbCqHjPJ1vYSOmkGSeSorvHyaM/edit?usp=sharing" target="_blank">https://docs.google.com/document/d/1UK94PxVlQtVSb2ns5TbCqHjPJ1vYSOmkGSeSorvHyaM/edit?usp=sharing</a></p>
<p>Given this design, you can only have an induced-draft fan on
the outlet. A forced-draft fan on the inlet would compress the
air, heating it up and negating the throttling (or
Joule-Thompson) effect on the low-pressure side. <br>
</p>
<p>At the end of the day, thermodynamics still says X amount of
shaft work has to be done to provide Y amount of cooling through
this process, so I'm still skeptical of it, especially at scale.
<br>
</p>
<p>And for those of you looking for something really boring to
read rather than work, here are the related patents. I haven't
read them myself. <br>
</p>
<p><a class="gmail-m_-4339801130891775252moz-txt-link-freetext" href="https://patents.google.com/patent/US8414847" target="_blank">https://patents.google.com/patent/US8414847</a></p>
<p><a class="gmail-m_-4339801130891775252moz-txt-link-freetext" href="https://patents.google.com/patent/US8986627B2" target="_blank">https://patents.google.com/patent/US8986627B2</a></p>
<p><a class="gmail-m_-4339801130891775252moz-txt-link-freetext" href="https://patents.google.com/patent/US10113774B2" target="_blank">https://patents.google.com/patent/US10113774B2</a><br>
</p>
<pre class="gmail-m_-4339801130891775252moz-signature" cols="72">Prentice</pre>
<div class="gmail-m_-4339801130891775252moz-cite-prefix">On 1/25/19 2:26 PM, Eric Moore wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div dir="ltr">Actually, it looks like Joule-Thompson cooling
to me (Especially given the "Joule Force" name). You've got
the air intake (ambient), then an expansion nozzle, into a
low-pressure region, which is created by the fan at the end.
So the outlet velocity of the air (and thus it's kinetic
energy) is higher than the inlet velocity, which would lower
the internal energy, and thus the temperature. Instead the
fins/nozzle/heatsink transfer heat to the expanding gas,
which exits a little above ambient temperature. I imagine
the drawback is you really need to get rid of that high
velocity hot air, and can't recirculate it, or the kinetic
energy would be converted back to thermal energy, and mess
it all up. The descriptions do all involve the exhaust air
being ducted to the outside. This article has the most
technical detail: <a href="https://www.nextplatform.com/2018/12/04/the-leading-edge-of-air-cooled-servers-leads-to-the-edge/" target="_blank">https://www.nextplatform.com/2018/12/04/the-leading-edge-of-air-cooled-servers-leads-to-the-edge/</a></div>
</div>
<br>
<div class="gmail_quote">
<div class="gmail-m_-4339801130891775252gmail_attr" dir="ltr">On Fri, Jan 25, 2019 at
11:33 AM Prentice Bisbal via Beowulf <<a href="mailto:beowulf@beowulf.org" target="_blank">beowulf@beowulf.org</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;padding-left:1ex;border-left-color:rgb(204,204,204);border-left-width:1px;border-left-style:solid">
<div bgcolor="#FFFFFF">
<p>You all know how much I like talking about heat
transfer and server cooling, so I decided to do some
research on this product:</p>
<p>Here's their website: <br>
</p>
<p><a class="gmail-m_-4339801130891775252gmail-m_8157281066646160146moz-txt-link-freetext" href="https://forcedphysics.com" target="_blank">https://forcedphysics.com</a><br>
</p>
<p>and here's their YouTube channel with 5 videos:<br>
</p>
<p><a class="gmail-m_-4339801130891775252gmail-m_8157281066646160146moz-txt-link-freetext" href="https://www.youtube.com/channel/UClwWeahYGuNl0THWVz1Hyow/videos" target="_blank">https://www.youtube.com/channel/UClwWeahYGuNl0THWVz1Hyow/videos</a> </p>
<p>This is really nothing more than an air-cooled
heatsink. I'm afraid I'm going to have to call BS on
this technology for the following reasons: <br>
</p>
<p>1. It still uses air as the primary cooling medium. I
just don't think air has adequate thermal conductivity
or thermal capacity to serve modern processor, no matter
what you do to it. <br>
</p>
<p>2. In the videos, they present highly idealized tests
with no control to use for comparison. How do I know I
wouldn't get the same results doing the same experiment
but using a similar duct fashioned out of sheet metal. <br>
</p>
<p>3. Using this technology means a complete redesign of
your server hardware and possibly your racks.</p>
<p>4. None of the information in the videos or on their
website really explains how this technology works, and
what really differentiates it from any other air-cooled
heat sink. Most people with a good invention are usually
excited to tell you how it works. Since they brag about
30 international patents for this, there's no need to
try to protect a trade secret. </p>
<p>5. This statement:</p>
<p> </p>
<blockquote type="cite">The fins work like teeth in a
comb, neatly orienting air molecules to point in the
same direction and arranging them into columns. </blockquote>
<p>Based on my education, this statement seems to be
completely devoid of science. <br>
</p>
<p>This statement seems to defy the laws of physics. Last
time I checked, unless an atom or molecule is at
absolute zero, it has movement, whether it's spinning or
vibrating, or both, so how can they get air molecules to
line up all in neat little rows, where the molecules are
all pointing the same way? </p>
<p>This also implies very laminar flow. As fluid velocity
increases that the diameter of the channel decreases,
the Reynolds Number increases. As the Reynold's number
goes up, turbulence increases, so mathematically, I
would expect this flow to be tubulent, and not laminar.
From my classes on heat transfer, turbulent flow around
the heat transfer surface increases heat transfer, so
laminar flow in this case wouldn't be a good thing. <br>
</p>
<p>Until they can provide better comparisons with real
servers in real data center environments, I'm going to
classify this as "snake oil"<br>
</p>
<p><a class="gmail-m_-4339801130891775252gmail-m_8157281066646160146moz-txt-link-freetext" href="https://en.wikipedia.org/wiki/Snake_oil" target="_blank">https://en.wikipedia.org/wiki/Snake_oil</a><br>
</p>
<pre class="gmail-m_-4339801130891775252gmail-m_8157281066646160146moz-signature" cols="72">Prentice</pre>
<div class="gmail-m_-4339801130891775252gmail-m_8157281066646160146moz-cite-prefix">On
1/24/19 3:54 PM, <a class="gmail-m_-4339801130891775252gmail-m_8157281066646160146moz-txt-link-abbreviated" href="mailto:Chuck_Petras@selinc.com" target="_blank">Chuck_Petras@selinc.com</a>
wrote:<br>
</div>
<blockquote type="cite"> <font face="sans-serif" size="2">Well,
this is interesting.</font> <br>
<br>
<font face="sans-serif" size="2">"According to Forced
Physics’ <</font><a href="https://urldefense.proofpoint.com/v2/url?u=https-3A__forcedphysics.com_&d=DwMFAw&c=-_uRSsrpJskZgEkGwdW-sXvhn_FXVaEGsm0EI46qilk&r=fawF3TRTwCqlaBkoLcxYCr4F4NRwCc64hmEgi9rHPpE&m=zr6lAlVphGxOQTXSElww9hGpqb9IZPik0_MN2v8Fqjs&s=lb4Hi9X8NKIYWe_e1RU3Cw4gr9Uz_B7n5pnCNY0ss3U&e=" target="_blank"><font color="blue" face="sans-serif" size="2">https://forcedphysics.com/</font>
[forcedphysics.com]</a><font face="sans-serif" size="2">> chief technology officer, David
Binger, the company’s conductor can help a typical
data center eliminate its need for water or
refrigerants and shrink its 22-MW load by 7.72 MW,
which translates to an annual reduction of 67.6
million kWh. That data center could also save a total
of US $45 million a year on infrastructure, operating,
and energy costs with the new system, according to
Binger. “We are solving the problem that electrons
create,” he said."</font> <br>
<br>
<font face="sans-serif" size="2">A Cooler Cloud: A
Clever Conduit Cuts Data Centers’ Cooling Needs by 90
Percent</font> <br>
<a href="https://urldefense.proofpoint.com/v2/url?u=https-3A__spectrum.ieee.org_energy_environment_a-2Dcooler-2Dcloud-2Da-2Dclever-2Dconduit-2Dcuts-2Ddata-2Dcenters-2Dcooling-2Dneeds-2Dby-2D90-2Dpercent&d=DwMFAw&c=-_uRSsrpJskZgEkGwdW-sXvhn_FXVaEGsm0EI46qilk&r=fawF3TRTwCqlaBkoLcxYCr4F4NRwCc64hmEgi9rHPpE&m=zr6lAlVphGxOQTXSElww9hGpqb9IZPik0_MN2v8Fqjs&s=VuDTSuinKPMpF6NCztFZkSGOVo3LD7MLjroIj_sn0ao&e=" target="_blank"><font color="blue" face="sans-serif" size="2">https://spectrum.ieee.org/energy/environment/a-cooler-cloud-a-clever-conduit-cuts-data-centers-cooling-needs-by-90-percent</font>
[spectrum.ieee.org]</a> <br>
<font face="sans-serif" size="2"><br>
<br>
Chuck Petras, PE**<br>
Schweitzer Engineering Laboratories, Inc<br>
Pullman, WA 99163 USA<br>
</font><a href="http://www.selinc.com/" target="_blank"><font face="sans-serif" size="2">http://www.selinc.com</font></a><font face="sans-serif" size="2"><br>
<br>
SEL Synchrophasors - A New View of the Power System
<</font><a href="http://synchrophasor.selinc.com/" target="_blank"><font face="sans-serif" size="2">http://synchrophasor.selinc.com</font></a><font face="sans-serif" size="2">><br>
<br>
Making Electric Power Safer, More Reliable, and More
Economical (R)<br>
<br>
** Registered in Oregon.<br>
</font> <br>
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