Previously, we talked about the single-threaded performance, CPU capacity and hardware cost difference between an extremely poor server model and processor SKU choice and a much better server model and processor SKU choice from about three and a half years ago. In that case, the bad choice only had about 34% of the single-threaded CPU performance and about 34% of the CPU capacity of the good choice processor SKU.
There was a $746.00 increase in the cost of the processor itself, and perhaps a $500.00 difference in the cost of a base Dell PowerEdge R620 compared to a base Dell PowerEdge R320 server. The SQL Server license cost would have been identical in either case, based on the number of physical cores.
Since the legacy hardware choice was so poor, that makes it even easier to get a significant increase in single-threaded CPU performance and overall CPU capacity by purchasing a brand new model server, using the best available processor at the same physical core count. A new model server will also have higher memory density and capacity and more PCIe 3.0 lanes available. It will also have a number of manageability advantages.
Dell’s 14th generation servers support the new 14nm Intel Xeon Scalable Processors (Skylake-SP) processors that have anywhere from four to 28 physical cores. In our case, we want to replace a legacy Dell PowerEdge R320 server that had one Intel Xeon E5-2407 v2 processor that had four physical cores, a base clock speed of 2.4GHz, no Turbo Boost, no Hyper-Threading, a relatively small 10MB L3 cache, a slow 6.4 GT/s QPI speed, three channels of DDR3-1066 memory support and 24 PCIe 3.0 lanes.
The best quad-core Intel Xeon Scalable processor SKU for a two-socket server is the Intel Xeon Gold 5122 processor, which has a base clock speed of 3.6GHz, a Turbo clock speed of 3.7GHz, Hyper-Threading, 16.5MB of L3 cache, six channels of DDR4-2666 memory support, and 48 PCIe 3.0 lanes, and a price of $1,221.00.
A bad choice at the same physical core count is the Intel Xeon Silver 4112 processor that has a base clock speed of just 2.6Ghz, a Turbo clock speed of only 3.0GHz, Hyper-Threading, 8.25MB of L3 cache, six channels of slower DDR4-2400 memory support, 48 PCIe 3.0 lanes, and a price of $473.00. Saving $748.00 by getting the cheaper processor is foolish, false economy for SQL Server usage.
A good server for a Xeon Gold 5122 processor is the new Dell PowerEdge R740 two-socket server. Even though this is a two-socket server, you can choose to only populate one socket to start with (which is what we will do here). One trade-off when you only use one processor in a two-socket server is that you cut the overall memory capacity of the server in half (until you add another processor later).
The main point here is that you should do this type of analysis when looking at new servers and selecting a particular processor for SQL Server 2016/2017 usage. You should definitely avoid the Intel Xeon Silver and Bronze lines for SQL Server usage, since you give up so much performance and scalability for a relatively small hardware cost reduction.
Additional Resources
My new Pluralsight course, SQL Server: Upgrading and Migrating to SQL Server 2016 has just been published. This is my eleventh course for Pluralsight, but the complete list of my courses is here.
Building on this online course is a new three day class, IEUpgrade: Immersion Event on Upgrading SQL Server, taught by myself and Tim Radney. The first round of this course will be taught in Chicago from October 11-13, 2017.
Finally, I will be presenting a half-day session called Migrating to SQL Server 2017 at the PASS Summit 2017 in Seattle, WA from October 31- November 3, 2017.
Here is a link to the complete series about upgrading SQL Server.