The Intel Xeon E5 v4 Review: Testing Broadwell-EP With Demanding Server Workloads
by Johan De Gelas on March 31, 2016 12:30 PM EST- Posted in
- CPUs
- Intel
- Xeon
- Enterprise
- Enterprise CPUs
- Broadwell
HPC: Fluid Dynamics with OpenFOAM
Computational Fluid Dynamics is a very important part of the HPC world. Several readers told us that we should look into OpenFOAM, and my lab was able to work with the professionals of Actiflow. Actiflow specializes in combining aerodynamics and product design. Calculating aerodynamics involves the use of CFD software, and Actiflow uses OpenFOAM to accomplish this. To give you an idea what these skilled engineers can do, they worked with Ferrari to improve the underbody airflow of the Ferrari 599 and increase its downforce.
We were allowed to use one of their test cases as a benchmark, however we are not allowed to discuss the specific solver. All tests were done on OpenFOAM 2.2.1 and openmpi-1.6.3. The reason why we still run with OpenFOAM 2.2.1 is that our current test case does not work well with higher versions.
We also found AVX code inside OpenFoam 2.2.1, so we assume that this is one of the cases where AVX improves FP performance.
As this is AVX code, the clock speed of our Xeon processors can be lower than Intel's official specifications, and turbo boost speeds are also lower. Despite the fact that on Broadwell the only cores that reduce their clock when running AVX code are the AVX-active cores themseves (the others can continue at higher speeds), OpenFOAM does not run appreciably faster on the top of the line Xeon E5 v4 than it did on the E5 v3.
It is not as if OpenFOAM does not scale: 22% more cores delivers 13% higher performance (E5-2699v4 vs E5-2695v4). No, our first impression is that the new Xeon v4 needs to lower the clockspeed more than the old one. The official specifications tell us that both the Xeon E5-2699 v4 and v3 should run AVX code at up to 2.6 GHz with all cores enabled. The reality is however that Broadwell runs at a lower clock on average.
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ltcommanderdata - Friday, April 1, 2016 - link
Does anyone know the Windows support situation for Broadwell-EP for workstation use? Microsoft said Broadwell is the last fully supported processor for Windows 7/8.1 with Skylake getting transitional support and Kaby Lake will not be supported. So how does Broadwell-EP fit in? Is it lumped in with Broadwell and is fully supported or will it be treated like Skylake with temporary support until 2018 and only critical security updates after that? And following on will Skylake-EP see any Windows 7/8.1 support at all or will it not be supported since it'll presumably be released after Kaby Lake?extide - Friday, April 1, 2016 - link
When MS says they are not supporting Skylake on Windows 7 DOES NOT MEAN it won't work. It just means they are not going to add any specific support for that processor in the older OS's. They are not adding in the speed shift support, essentially.For some reason the press has not made this very clear, and many people are freaking out thinking that there will be a hard break here will stuff will straight up not work. That is not the case.
Broadwell has no new OS level features over Haswell (unlike Skylake with speed shift) so there is nothing special about Broadwell to the OS. As the poster above mentions, they are all x86 cpu's and will all still work with x86 OS's.
The difference here is between "Fully Supported" and Compatible. Skylake and even Kaby Lake will be compatible with WIndows 7/8/8.1.
aryonoco - Friday, April 1, 2016 - link
Johan, this is yet again by far the best Enterprise CPU benchmark that's available anywhere on the net.Thank you for your detailed, scientific and well documented work. Works like this are not easy, I can only imagine how many man hours (weeks?) compiling this article must have taken. I just want you to know that it's hugely appreciated.
JohanAnandtech - Friday, April 1, 2016 - link
Great to read this after weeks of hard work! :-Dfsdjmellisse - Friday, April 1, 2016 - link
hello, i want to buy E5-2630L v4any one can give me website for buy it ?
Best regards
HrD - Friday, April 1, 2016 - link
I'm confused by the following:"The following compiler switches were used on icc:
-fast -openmp -parallel
The results are expressed in GB per second. The following compiler switches were used on icc:
-O3 –fopenmp –static"
Shouldn't one of these refer to icc and the other to gcc?
JohanAnandtech - Friday, April 1, 2016 - link
Pretty sure I did not mix them up. "-fast" does not work on gcc neither does -fopenmp work on icc.patrickjp93 - Friday, April 1, 2016 - link
Um, wrong and wrong. -Ofast works with GCC 4.9 and later for sure. And -fopenmp is a valid ICC flag post-ICC 13.JohanAnandtech - Saturday, April 2, 2016 - link
"-fast" is a typical icc flag. (I did not write -"Ofast" that works on gcc 4.8 too)extide - Friday, April 1, 2016 - link
Johan, if you read the comment, you can see that you mention icc for BOTH.