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<font face="Times New Roman">Some additional comments:<br>
<br>
If you need an idea of about how computational intensive a WIEN2k
calculation might be for around 60 atoms per cell or more. The
links below and links in those posts might be helpful:<br>
<br>
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14035.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14035.html</a><br>
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg01420.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg01420.html</a><br>
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg05784.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg05784.html</a><br>
<br>
The hardware specifications for the i7-7700K and E5-2623 v3
processors should be at the links:<br>
<br>
<a class="moz-txt-link-freetext" href="https://ark.intel.com/products/97129/Intel-Core-i7-7700K-Processor-8M-Cache-up-to-4_50-GHz">https://ark.intel.com/products/97129/Intel-Core-i7-7700K-Processor-8M-Cache-up-to-4_50-GHz</a><br>
<a class="moz-txt-link-freetext" href="http://ark.intel.com/products/83354/Intel-Xeon-Processor-E5-2623-v3-10M-Cache-3_00-GHz">http://ark.intel.com/products/83354/Intel-Xeon-Processor-E5-2623-v3-10M-Cache-3_00-GHz</a><br>
<br>
</font><a class="view-modal info-modal" data-modal="tt-MaxMem"><span></span></a>The
specifications look fairly similar. So maybe there would not be too
much of a difference in the WIEN2k calculation run times between the
two.<br>
<br>
The i7-7700K supports a Max Memory Size of 64 GB. The E5-2623 v3
could have a major advantage when it comes to supporting a Max
Memory Size of 768 GB. However, if the motherboard the E5-2623 v3
goes on does not have memory expansion slots for more than 64 GB or
if you never plan to add additional memory modules to increase the
memory beyond 64 GB, then that would not matter.<br>
<br>
The i7-7700K does have about a 1 GHz faster processor frequency and
it looks like it supports a faster RAM (DDR4-2133/2400, while the
E5-2623 v3 supports a slower DDR4 with frequency of 1600 or 1866
MHz). So this might give it better performance than the i7-7700K if
the calculation uses less than 64 GB of RAM. Above 64 GB, the
workstation would likely use virtual memory and disk caching may
significantly slow a calculation (whereas the E5-2623 v3 with more
than 64 GB should extend the limit of this RAM bottleneck). The
i7-7700K also supports DDR3L-1333/1600. If both the i7-7700K and
E5-2623 v3 workstations happen to use the same DDR3 1600 RAM, then
no speed up or slow down is expected from the RAM frequency.<br>
<br>
More importantly than all that may be the launch date for the
E5-2623 v3 of Q3'14, while Q1'17 for the i7-7700K. The Xeon E5-2623
v3 has been around awhile. So Linux distributions most likely have
drivers that support this processor. With the i7-7700K being so
new, you might have to be more cautious. If you decide to get the
i7-7700K, I recommend checking that the Linux distribution, compiler
(in particular if you plan to use a non-Intel compiler like
gfortran), and libraries (such as a blas library with the non-Intel
compiler) that you will be using are able to support and recognize
the processor.<br>
<br>
As an example, I think it was the Intel HD Graphics 530 onboard the
Intel Skylake processors when they were first launched that didn't
have a good Linux driver [
<a class="moz-txt-link-freetext" href="https://askubuntu.com/questions/698168/cant-get-intel-hd-graphics-530-skylake-i7-6700-to-work">https://askubuntu.com/questions/698168/cant-get-intel-hd-graphics-530-skylake-i7-6700-to-work</a>
]. If I recall correctly, the graphics were broken (or of poor
quality) for several months until the drivers were finally released.<br>
<br>
Of note, there is also seems to be a E5-2623 v4:<br>
<br>
<a class="moz-txt-link-freetext" href="http://ark.intel.com/products/92980/Intel-Xeon-Processor-E5-2623-v4-10M-Cache-2_60-GHz">http://ark.intel.com/products/92980/Intel-Xeon-Processor-E5-2623-v4-10M-Cache-2_60-GHz</a><br>
<br>
<div class="moz-cite-prefix">On 9/18/2017 6:54 PM, Yundi Quan wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAHRiqkQj3P936NTDATKTxH989N+aEJP=dcxjHnHtbOq4cAOGrA@mail.gmail.com">
<div dir="ltr">hi,
<div><br>
</div>
<div>4 cores with 8 threads is probably OK for using WIEN2k to
study transition metal oxides. For post-processing tools, such
as wien2wannier, it requires more memory. But 64 GB is enough
in most cases. I once bought a Dell XPS with 4 cores and 8
threads, 16 GB memory back in 2011. It worked well for most of
my calculations. Hope this helps.</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
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<div class="gmail_extra"><br>
<div class="gmail_quote">On Mon, Sep 18, 2017 at 2:44 PM,
Karsten Küpper <span dir="ltr"><<a
href="mailto:kkuepper@uos.de" target="_blank"
moz-do-not-send="true">kkuepper@uos.de</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">Dear
WIEN2k-community,<br>
<br>
We want to buy a workstation dedicated to run WIEN2k.<br>
Our aim is to calculate mostly transition metal oxides with
unit cells ranging from 24 - 128 atoms supercells.<br>
We are thinking about a workstation with at least 4 cores,
at least 64 GB RAM, and a 1TB SSD as a starting point.<br>
<br>
1) May that be a reasonable choice?<br>
<br>
2) Has anybody experiences with the i7-7700K 4.2 GHz (maybe
also compared to Intel-Xeon E5-2623 processors), as there
is no benchmark test available on the WIEN2k homepage by
now.<br>
<br>
Thanks for your efforts in advance!<br>
<br>
Kind regards<br>
Karsten Küpper<br>
</blockquote>
</div>
</div>
</blockquote>
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