Understanding Server Memory: Tips for Adding Additional Capacity

In my many travels in the world of online sales, the one topic in my sphere of influence that appears to stump many of our customers is the issue of memory and adding additional capacity to their existing infrastructure. Many many times we have customers that will purchase 1 module thinking they can add it to their system and it will give them the needed boost they desire. Unfortunately, it isn't that easy and there are a few considerations to take into account that I hope this blog posts addresses.

1. There are MANY difference types of memory.

• Desktop Ram (Also known as UDIMM or Long DIMM)
• Laptop Ram (Also known as SODIMM)
• Server Ram (Also known as RDIMM)
• Load Reduced Server Ram (Also known as LRDIMM)
• Optane Memory (NV-DIMM)

If you have an Intel or AMD based PC, you can only buy UDIMM memory. Server memory (what we sell on our stores) will not work for you in any configuration. You can tell if you have a PC by the processor. If your processor is NOT Intel XEON or AMD EPYC, chances are you have a PC and you need to buy UDIMM memory for your system.

Server memory comes in many flavors depicted by capacity (how many gigabytes it is), speed (denoted PC3-12800R or PC4-2933Y). 12800R is the speed of the DDR3 memory. 2933Y is the speed of the DDR4 memory. The speed of the memory your system supports is always referenced by the processor. Your motherboard may list compatible memory but the processor will define exactly the speed the memory will operate. If mixed speeds are installed within the same system, the system will default to the slowest module installed. I never recommend someone mix and match modules within their system as it generally causes problems and is far from optimal. My suggestion is always to grab a memory module from an existing system, find the manufacturer model or part number on the module, and buy the exact same memory if you have sockets available to add memory. I should note that it is best to add memory in pairs. Two RDIMMs per installed CPU. If your system has 2 CPUs you should add memory in fours. If your system is operating on a single CPU, you should add memory in twos.

After speed, the next component of memory to pay attention to is the ranking. This is typically listed as 1Rx4, 2Rx4, 2Rx4 or can be quad ranked like 4Rx4. This identifies how many chips are installed on the memory PCB board. This should ALWAYS match what is already in your system. If you have a server that has something like an E5-2600 series v4 CPU, I would recommend to use 2Rx4 ranking memory. 2Rx4 is the most commonly used memory whether Xeon Silver, Gold, etc. If you need a different ranking you likely have some specialized system type, like a blade and should follow the manufacturers technical specifications to be sure you are buying the correct memory for your system type.

The last piece to pay attention to on memory is the voltage. Memory can be 1.5v or 1.2v and is defined by the manufacturers part number. The newer memory runs at lower voltages but higher memory speed can require a higher voltage. If you are following the manufacturers technical guidebook (Dell) or quickspecs (HP), it is almost impossible to mix this up and get the wrong part. In the server world, memory is never overclocked because stability is the most important factor in the systems existence vs speed or performance.

With that being said, I have some key takeaways or TLDR statements to help you order the correct memory from GIGDATA.

1. We do not sell PC memory. No memory we sell will work for your PC.
2. Always buy the same memory you are already using. Match the type and speed to your processor. If you go with a larger module capacity wise, replace them all.
3. Always buy memory in pairs 2 or more per installed CPU.

If you have questions on what memory we have available for your exact system, please feel free to email us at web@gigdataserv.com or use the chat function on our website.

Thanks for reading!