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
Sharing Cache and Memory Resources
In a virtualized environment, the hosted VMs are sharing both the CPU caches and the overall DRAM memory bandwidth. One cache-hungry application can quickly hog most of the shared L3 caches, and a bandwidth intensive one can do the same with the available and shared memory bandwidth. These VMs create the "noisy neighbor" problem. That is bad news for anyone consolidating a lot of VMs on top of a Xeon server, but it is complete show stopper for telco and other scenarios where service providers want to guarantee "Quality-of-Service" (QoS) and thus predictable latency. For Intel this is a notable scenario to address, as the telco market is one of the few markets where the Xeons still have some room to grow. Many telco applications still run on proprietary boxes, which makes virtualization a tantalizing option if Intel can deliver the necessary latency.
Haswell had already some features to monitor cache usage, which in turn allowed you to identify the noisy neighbors. However the "Resource Director Technology" (RDT) of Broadwell can do a lot more.
RDT can not only monitor L3 cache usage and memory bandwidth, but it can also allocate L3-cache space on a per thread/process/virtual machine basis. Threads are assigned a Resource Monitoring ID. Eight of these RMID are available per core/cache slice. Sixteen different classes of service can be assigned to an RMID: higher priority threads/applications can get a higher class, and thus a larger portion of the L3-cache.
Intel has already demonstrated an application that made use of these new MSRs to read out memory bandwidth and L3 cache consumption on different levels.
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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.