Server RAM: How to Build a Low-Power Server – Kingston Technologies
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Server RAM: How to Build a Low-Power Server – Kingston Technologies


Hi, I’m Mike with Kingston. How you use memory, and which type you use, requires a solid understanding of how to balance power, capacity and performance. Using low voltage server memory and optimizing your installation with a low power strategy, can save 10% or more of your server’s total power consumption. This strategy can multiply across a data center, adding up to real savings. In this video, I’m going to show you how to configure your server memory to minimize power consumption. For more information and available options, please refer to the Kingston website and the paper entitled Minimizing Power for Server. When it comes to installing or upgrading your server with memory, there are many options and configurations available. Price is usually the first thing you’ll look at when making a decision about which parts to buy. But price shouldn’t be your only consideration, as an effective memory strategy may prove less costly over the long term. In this demonstration, I’ll show two configurations designed to achieve 256GB of memory in an HP ProLiant DL380p G8 server. The first configuration will feature standard DDR3 memory operating at 1.5V, and the second configuration will feature DDR3L low voltage memory operating at 1.35V. I’ll use a simple power meter to measure the server’s total power draw while running software designed to simulate heavy server stress on the processors and memory. To achieve 256GB in the first configuration, I chose 16 of Kingston’s DDR3-1600 Dual Rank Registered DIMMs, each operating at 1.5V. This will represent a common memory upgrade path and a baseline for our comparison. The HP ProLiant DL380p G8 has a total of 24 available memory sockets, with each Xeon E5 processor having its own bank of 12. To optimize for quad channel memory performance, I’ve installed two kits of four, or 8 DIMMs, for each processor. For this demonstration, we won’t be using the third memory bank. In order to measure the total power draw of the server, we’ll need to stress the processors and memory. When not processing applications or big data, most modern servers are designed to sip power. As you can see by the power meter, our server is only using around 115 watts. As the applications load, you can see the total power draw jump as the processors and memory kick into high performance to handle the calculations. The watts used will level as the server reaches its peak performance for these applications. Ours settles in at around 320 watts. With these numbers plotted on our graph, let’s test the next configuration. Kingston offers a range of DDR3L low voltage server memory parts. With a power saving strategy in mind, I chose to install 8 of Kingston’s 32GB DDR3L 1066 Quad Rank Registered DIMMs, operating at 1.35V. Eight 32GB DIMMs will achieve a capacity of 256GB, the same capacity as our first configuration, but using only using half the number of memory sockets. Fewer memory sockets used would mean less power will be consumed by the memory banks. The low voltage DDR3L chips on these DIMMs will use about 10% less power compared to standard DDR3 at 1.5V. Another benefit comes from using Quad Rank DIMMs, which draw less power than Single or Dual Rank DIMMs, and operate at lower speeds than standard DDR3, saving even more power. Let’s first check the watts on the power meter as the system is in idle. We’re checking in at around 110 watts. As we run the stress test, again we can see the power usage jump. But notice where it levels off. Under the same server load as the first configuration, we’re now at about 280 watts. That’s 40 watts less, a power savings of 12%. Memory is just one piece of the power savings equation. Combined with low power processors, green power supplies, and Solid State Drives, your server configuration can have a major impact on the energy costs for your data center. Kingston offers a full range of server memory modules and products designed to optimize power savings, performance, and capacity. This video on minimizing power consumption for servers is one in a series of Kingston Memory Best Practices. Others in the series provide the information and product considerations needed to maximize performance and capacity. Kingston also offers an experienced pre-sales technical support staff to help you determine which configuration is ideal for your environment. Please ask your Kingston Representative about our “Ask a Kingston Expert” program in your region.

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