If you have read my SQL Server Hardware book, or ever heard me do one of my hardware presentations, you have probably heard my exhortations to “Never let anyone talk you into reusing old hardware for a new version of SQL Server”. This is especially true with SQL Server 2012 Enterprise Edition and its core-based licensing model. In order to illustrate this point, I want to compare a couple of different, common server models from Dell, from a SQL Server 2012 Enterprise Edition perspective. The reason that I focus on Enterprise Edition is because of the 64GB RAM limit for Standard Edition and because of all of the compelling features in Enterprise Edition that are so valuable for mission critical database servers.
The “old” model server that I want to use for this comparison is a Dell PowerEdge R900 server, which is a 10th generation, four-socket, 4U, rack-mount server that used the Intel Xeon 7200 series, Intel Xeon 7300 series and the Intel Xeon 7400 series processors, culminating in the Intel Xeon X7460 processor that was released in Q3 of 2008. This processor was the hot ticket in late 2008 through early 2010 (when the Nehalem-based Intel Xeon 7500 series was introduced in Q1 of 2010). I can remember unsuccessfully begging my CTO at NewsGator to let me get a new R900 server during that time frame, but I never won that battle! I often see customers that are still using this model server in production, so it is not ancient by any means.
The current model server I am going to use for the comparison is the Dell PowerEdge R720xd server, which is a 12th generation, two-socket, 2U, rack-mount server that uses the Intel Xeon E5-2600 series processors. The top of the line model for the Intel Xeon E5-2600 series is the Intel Xeon E5-2690, which is the current champion for single-threaded processor performance according to recent TPC-E OLTP benchmark results.
Comparing the Processors
The 45nm Intel Xeon X7460 “Dunnington” is a six-core processor that has a clock speed of 2.66GHz. It does not have Intel Hyper-Threading or Turbo Boost Technology, and it does not support non-uniform memory access (NUMA). In fact, it was the last generation processor in the 7000 sequence to have a symmetric multiprocessing (SMP) architecture. SMP machines had increasing problems with memory contention causing performance and scalability issues as the number of sockets increased in the server, especially once you went above four sockets.
The 32nm Intel Xeon E5-2690 “Sandy Bridge-EP” is an eight-core processor that has a base clock speed of 2.9GHz. It can use Turbo Boost to increase the speed of individual processor cores up to 3.8GHz, and it has Hyper-Threading so that you will have 16 logical processors available to the operating system. The Xeon E5-2690 does have NUMA support, and the on-board memory controller has four memory channels. The E5-2690 has support for the newer PCI-E 3.0 standard which gives twice the total bandwidth of the older PCI-E 2.0 standard. This is a much better processor than the old Xeon X7460.
Comparing the Server Capacities
The Dell PowerEdge R900 server could have four, six-core Intel Xeon X7460 processors for a total of 24 physical cores in the system. The R900 has 32 DIMM memory slots that can each hold 8GB FB-DIMMs for a total of 256GB of RAM in the system. There are seven PCI-E 2.0 slots in this server, with four x8 slots and three x4 slots. There are also eight 2.5” internal drive bays that support 6Gbps SAS drives.
The Dell PowerEdge R720xd server could have two, eight-core Intel Xeon E5-2690 processors for a total of 16 physical cores in the system. With hyper-threading enabled, you would have 32 logical cores. The R720xd has 24 DIMM memory slots that each hold 32GB DDR3 ECC DIMMs for a total of 768GB of RAM. Realistically, it does not make economic sense to use 32GB DIMMs since they still cost about $1500 each! That means you would likely choose 16GB DIMMs for a total capacity of 384GB of RAM in the system. There are six PCI-E 3.0 slots in this server, with two x16 slots and four x8 slots. There are also (26) 2.5” internal drive bays that support 6Gbps SAS drives. The R720xd supports 50% more RAM (using affordable 16GB DIMMs), triple the PCI-E slot bandwidth, and more than triple the internal drive bay capacity compared to the R900.
Comparing the TPC-E Performance
There is actually a TPC-E submission for a Dell PowerEdge R900 server with four Xeon X7460 processors from August 19, 2008, with a score of 671.35. Dividing 671.35 by 24 physical cores gives us a score of 27.97 per physical core, which is quite low by modern standards.
There are no TPC-E submissions for a Dell PowerEdge R720xd server, so I picked one for a Fujitsu PRIMERGY RX300 S7 with two Xeon E5-2690 processors from July 5, 2012, with a score of 1871.81. Dividing 1871.81 by 16 physical cores gives us a score of 116.99 per physical core, which is much better than the older R900 system!
Comparing the SQL Server 2012 Enterprise Edition Licensing Costs
The Dell PowerEdge R900 server with four Xeon X7460 processors has 24 physical processor cores that will each require a SQL Server 2012 Enterprise Edition core license that costs $6874.00. This will cost you $164,976.00 for the SQL Server 2012 license costs.
The Dell PowerEdge R720xd server with two Xeon E5-2690 processors has 16 physical processor cores that will each require a SQL Server 2012 Enterprise Edition core license that costs $6874.00. This will cost you $109,984.00 for the SQL Server 2012 license costs. The savings in license costs compared to the R900 would pay for the server and leave about $35K available for other uses.
Comparing the SQL Server 2008 R2 Enterprise Edition Licensing Costs
The Dell PowerEdge R900 server with four Xeon X7460 processors has 4 physical processor sockets that will each require a SQL Server 2008 R2 Enterprise Edition processor license that costs $27,999.00. This will cost you $111,996.00 for the SQL Server 2008 R2 license costs.
The Dell PowerEdge R720xd server with two Xeon E5-2690 processors has 2 physical processor sockets that will each require a SQL Server 2008 R2 Enterprise Edition processor license that costs $27,999.00. This will cost you $55,998.00 for the SQL Server 2008 R2 license costs. The savings in license costs compared to the R900 would pay for the server and leave about $35K available for other uses. Even if you are going to use SQL Server 2008 R2 Enterprise Edition instead of SQL Server 2012 Enterprise Edition, you will still save money and have a faster server with more overall capacity by buying the new server.
Reusing your existing Dell PowerEdge R900 server for SQL Server 2012 Enterprise Edition would cost you $54,992.00 in additional SQL Server 2012 license costs to have about 36% of the TPC-E performance, compared to buying a new Dell PowerEdge R720xd server with two Xeon E5-2690 processors. This new server would cost roughly $15-20K depending on how you configured it and how much of a discount you got from your sales representative. This new server could have 50% more RAM (with 16GB DIMMs), triple the PCI-E slot bandwidth, and more than triple the internal drive bay capacity compared to the R900. The R720xd server would also use less power, and only take up 2U of rack space. Your net savings from buying the new server would be in the $35-40K range. If this is not good enough, I have an alternate configuration that would save even more money!
Instead of using the eight-core Xeon E5-2690 processors, you could choose the four-core Xeon E5-2643 processors for your new Dell R720xd server. This would reduce your hardware cost for the new server by about $2000.00 (since the processors are less expensive), and it would reduce your SQL Server 2012 licensing costs by 50%, since you would only have to have eight processor core licenses for a total of $54,992.00. This would give you a net savings of about $91-96K if you bought the new server. Since the E5-2643 has a base clock speed of 3.3GHz (with Turbo Boost to 3.5Ghz), you would actually see better single-threaded performance than with the E5-2690. You would give up some capacity and scalability compared to the E5-2690, but it would still be a big improvement over the existing R900 server. I would estimate that a two socket-server with two Xeon E5-2643 processors would have a TPC-E score of about 1029, which is still significantly better than the old R900 server.