Memory Types Udimm, RDIMM, LRDIMM

Types of memory

at present, the server's memory bus technology is basically not much change, still use DDR3 Technology ,DDR3 is the parallel transmission technology, so to ensure the validity of the parallel data transmission, we must work the memory bar , There are currently three types of memory bars: Udimm, RDIMM, LRDIMM .

1.UDIMM: Also known asunbuffered DIMMs. When data is fromCPUwhen uploading to each memory particle,UdimmRequirements GuaranteeCPUThe data transfer distance between each memory particle is equal so that the parallel transfer is valid. This requires a very high manufacturing process and is extremely difficult to achieve high density and frequency. SoUdimmboth capacity and frequency are low. However,Udimmsince theCPUand memory without any cache, so the latency at the same frequency is small. The current common is a single capacity2GB/4GB, the highest frequency can only reach1.33GHz.

2.RDIMM: Also known asregistered DIMMs. In order to ensure the validity of the parallel transmission,RDIMMA register is added to the memory strip to forward it. It is locatedCPUand memory particles, which reduces the distance between parallel transmissions. And because the register is highly efficient,RDIMMdensity and frequency are easy to improve. RDIMMis currently a more mainstream memory, a single capacity in2~32GBbetween, the frequency also has1.33GHzand the1.6GHztwo options. Most2This type of memory is typically configured at the factory with a common configuration of the server.

3.LRDIMM: Also known asLoad Reduced DIMMs. RDIMMAlthough the transmission is more efficient, the size of the register is limited, when the memory particles in a single memory are at the highest density4 Rankwhen deployed, the effectiveness and frequency of parallel transmissions can be significantly reduced. For example, when using32G RDIMMcan only be deployed on each memory channel of the server2memory bar, and can only run on800MHz.

To summarize:

1.from a price point of view,RDIMMrelatively moderate. Small-capacityUdimmcheaper, but due to the high manufacturing process requirements, large capacityUdimmPrice even more thanRDIMM. LRDIMMPrice aboveRDIMMwith theUdimm.

< Span lang= "en-US" style= "Background-color:inherit;" xml:lang= "en-us" >2. lrdimm can support to maximize total memory capacity. However, the memory capacity required by the primary application is typically deployed by deploying the rdimm . Span style= "font-family: ' The song body '; background-color:inherit;" > can be achieved.

< Span lang= "en-US" style= "Background-color:inherit;" xml:lang= "en-us" >3. rdimm support 1.6ghz

< Span lang= "en-US" style= "Background-color:inherit;" xml:lang= "en-us" >4. from a delay point of view, although the same frequency under the udimm latency is minimal, but rdimm can support 1.6ghz to lower the delay with higher frequencies.

5. from the power consumption point of view,the LRDIMM is highest,RDIMM and Udimm are lower.

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If you need the maximum memory capacity, you must use the LRDIMM If you do not need the maximum memory capacity, use the RDIMM ( 1.6GHz performance, price, and scalability are good, and if you consider power consumption, you can use low voltage ddr3l memory, and control its running at lower frequencies.

Memory Types Udimm, RDIMM, LRDIMM