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<p>How much power does that system use at full-tilt? I'm guessing
about 2250 - 2500 kW. <br>
</p>
<pre class="moz-signature" cols="72">Prentice </pre>
<div class="moz-cite-prefix">On 08/22/2016 07:40 PM, Stu Midgley
wrote:<br>
</div>
<blockquote
cite="mid:CAEM1RsWsfEHVqLK2YpcbPKGZFRXfebB_V_7nszGPpc8uFFHKsA@mail.gmail.com"
type="cite">
<div dir="ltr">I measured the power draw of our 2RU 8 phi nodes
with and without fans... the fans draw about 20% power.
<div><br>
</div>
<div>On a 2200kW node that's considerable.</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Tue, Aug 23, 2016 at 5:36 AM, Mark
Hahn <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:hahn@mcmaster.ca" target="_blank">hahn@mcmaster.ca</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex"><span
class="">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
Extra, the direct contact cooling stuff must still have
the fans in the<br>
nodes to keep the dimms/disks/power supplies cool...
thus use considerably<br>
more power than nodes without fans.<br>
</blockquote>
<br>
</span>
why do you say "considerably"? 1u muffin fans are annoying
and not that efficient, but even 1U could still use
blowers. and it's not as if<br>
you need a lot of airflow to keep 5-20W of support hardware
cool.<br>
(that would be for non-extreme numbers of disks/dimms/nics -
though it occurs to me that motherboards also have some
power regulation in them,<br>
and if 2 sockets are drawing 250w, then 90% efficient
regulation would still mean 28W extra heat to dissipate.)<br>
<br>
iirc a typical 1U fan dissipates up to ~3W, but that's only
when running full on (screaming 14krpm...). not to mention
the wide availability of simple 4-system-in-2u chassis (more
efficient fans).<br>
</blockquote>
</div>
<br>
<br clear="all">
<div><br>
</div>
-- <br>
<div class="gmail_signature" data-smartmail="gmail_signature">Dr
Stuart Midgley<br>
<a moz-do-not-send="true" href="mailto:sdm900@sdm900.com"
target="_blank">sdm900@sdm900.com</a></div>
</div>
<br>
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</pre>
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