If you haven’t heard, Intel’s coming out with a new CPU architecture this year and it is a bit different than what you are used to. If you haven’t started re-architecting your plans for future blade servers, now is the time to begin.
New Memory Architecture
This year, Intel will release their 3rd Generation Xeon SP processor, code name “Ice Lake.” Based upon information obtained on the world wide web, this new CPU architecture will introduce a shift from six to eight memory channels. Although this may seem trivial, it’s an important change that will impact how you achieve best performance on your blade servers.
First, a little history lesson. The existing Intel CPU offering (2nd Generation Xeon SP, aka “Cascade Lake”) was built with 6 memory channels. This was a huge change from the previous E5 architecture that relied on 4 memory channels. When Cascade Lake became available with its 6 memory channel designs, many organizations hated it. It was slower and didn’t perform the way they expected. The culprit – they were still using the same memory configuration they did with older systems using only 4 memory channels. The result was 2 memory channels being unused equaling about a 30% drop in available bandwidth.
8 Memory Channels vs 6
In order to stop history from repeating itself, you need to start preparing for an 8 memory channel design on your blade servers. Now is the best time to plan, because most blade server vendors aren’t quoting yet, so when they do, make sure you adjust for 8 memory channels. This means instead of building specs with 96GB (using 8GB DIMMs), plan for 128GB. Instead of 192GB DIMMs, plan for 256GB. I haven’t seen bandwidth numbers like I show above, but I imagine they will be similar: around the 30% difference.
From what I’m hearing, 8 memory channels are around to stay, so the sooner you move to using all 8 channels on your blade server design, the better performing your applications will run.
Kevin Houston is the founder and Editor-in-Chief of BladesMadeSimple.com. He has over 20 years of experience in the x86 server marketplace. Since 1997 Kevin has worked at several resellers in the Atlanta area, and has a vast array of competitive x86 server knowledge and certifications as well as an in-depth understanding of VMware and Citrix virtualization. Kevin has worked at Dell EMC since August 2011 is a Principal Engineer and Chief Technical Server Architect supporting the East Enterprise Region at Dell Technologies. He is also a CTO Ambassador in the Office of the CTO at Dell Technologies.
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