DDR-SDRAM memory at a glance

Fast working memory in the generation change

DDR RAM is mostly used as main memory. This designation makes it clear that it is a memory that contains the programs or parts of programs that are currently being executed and the required data. Memory modules in the DIMM format are mainly used in servers and PCs. SO-DIMM are used in notebooks.

DDR-SDRAM for servers

Technical terms: DDR-SDRAM at a glance

DDR RAM: Double Data Rate

In DDR RAM, unlike the older SDR RAM, the data bits are transferred on the rising and falling edges of the clock signal. Equivalently, there are also procedures with fourfold (Quadruple Data Rate, QDR) or even eightfold (Octal Data Rate, ODR) data rate.

DIMM: Dual Inline Memory Module

In contrast to single inline memory modules (SIMMs), DIMMs, i.e. double-row memory modules, have connection contacts on the front and on the back of the circuit board, which carry different signals. Usually, memory chips are also installed on both sides.

ECC Working memory: Error-Correcting Code Memory

ECC means that the memory module has the ability to detect and correct 1 and 2 bit errors if the motherboard and BIOS support it.

DDR-SDRAM at a glance

Technical terms: DDR-SDRAM at a glance

FBDIMM Working memory: FB = Fully Buffered Dual In-Line Memory Module

FBDIMM are DRAM modules in which the memory chips are not directly connected to the computer, but which contain another component for control (the buffer). They are considered the successor to Registered modules, both of which are primarily used for server and workstation applications.

RDIMM Memory: RDIMM = Registered Dual In-Line Memory Module

Register module refers to a type of memory module that is often used in the main memory of servers and workstations. The goal of the technology is to reduce the electrical load on the memory controller with additional registers, thereby increasing the number of memory chips that can be connected, as well as data integrity.

UDIMM Memory: UDIMM = Unregistered Dual In-Line Memory Module

This type of memory, on the other hand, does not use any additional registers. It is therefore more frequently installed in home PCs for economic reasons.

Identifying RAM modules: Small differences with a big effect

Designs of DDR SDRAM


Corner specifications of the DDR SDRAM families

ChipsModulesClockI/O clockEffective clockTransmission rates
DDR-200 – DDR-400PC-1600 – PC-3200100 – 200 MHz100 – 200 MHz200 – 400 MHz1.6 – 3.2 GB/s
DDR2-400 – DDR2-1066PC2-3200 – PC2-8500100 – 266 MHz200 – 533 MHz400 – 1066 MHz3.2 – 8.5 GB/s
DDR3-800 – DDR3-2133PC3-6400 – PC3-17000100 – 266 MHz400 – 1066 MHz800 – 2133 MHz6.4 – 17.0 GB/s
DDR4-1600 – DDR4-3200PC4-12800 – PC4-25600200 – 400 MHz800 – 1600 MHz1600 – 3200 MHz12.8 – 25.6 GB/s
DDR5-3200 – DDR5-8400PC5-25600 – PC5-67200200 – 525 MHz1600 – 4200 MHz3200 – 8400 MHz2× 12.8 – 2× 33.6 GB/s

Starline contact

Any questions? Please contact us.

Konrad Beyer has been with us since 2006 and has made a name for himself as an expert for network and IT security. He has expertise to almost all topics: from operating systems- Windows, Linux, macOS and VMware- to special fields- FC, iSCSI, Tape and NAS- to the product lines of Infortrend and Tiger Technology. As a human firewall, he is committed to ensuring that our internal systems run securely and that no malware infects our intranet. The hobby sailor also has the Starline telephone system firmly under control.

Konrad Beyer
Technical Support