Unless those DC rack supplies are ten times more expensive to replace and more likely to fail than a server power supply and harder to find.<br><br><br><div class="gmail_quote">On Dec 21, 2007 1:52 PM, Jonathan Hutchins &lt;&gt; wrote:
<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">The point of all this is that instead of every piece of equipment having<br>it&#39;s own switching power supply, with fan, you supply the required
<br>voltages to the whole rack from a common pair of fail over power supplies.<br>Each box then gets it&#39;s own +12,+5, and -5 (or whatever), and we have one<br>less component per unit to fail.<br><br>Converting the power once then distributing it really does beat
<br>distributing the AC and converting it at each unit, there are savings in<br>equipment cost, efficiency, and cooling.<br><br>Because of this, a 48 volt distribution system doesn&#39;t make as much sense,<br>nor &nbsp;does it offer as much advantage over a 120/240V AC distribution
<br>system.<br><div><div></div><div class="Wj3C7c"><br></div></div></blockquote></div><br>