Computer Memory Part 1: DRAM and Modules

Computer Memory Part 1: DRAM and Modules


Memory, being one of the primary portions of Advanced MP Technology’s (AMPT) business, is used for storing and/or programming bits of information. This includes many different commodities that are consistently changing: DRAM, SRAM, flash, EPROM, and modules.


To keep up with the changing environment of the memory market, in-depth product knowledge is crucial for procurement professionals. And that is why we decided to start a series of blogs on computer memory. Today, we will cover DRAM and modules.


DRAM (Dynamic Random Access Memory)


What is it? A type of random-access memory that stores each bit of data within a separate capacitor. The capacitor can be either charged or discharged, which represent the two values of a bit. Since leakage will occur, the capacitors will slowly discharge and the information fades until the charge is refreshed periodically. The refresh requirement is why it is called “dynamic”.


Major Producers: Micron, Hynix, and Samsung


News of Today: Fluctuating DRAM prices over the past few years, as a result of an oversupply of DRAM chips in the market, have a profound impact on companies in the semiconductor sector, such as Micron. Since then, many companies have dwindled out of the DRAM business, leaving only three main players. If the potential buying deal between Chinese company Tsinghua Holdings and Micron Technology go through, the landscape of the DRAM market is facing some big changes.

Though the latest technology, DDR4, is immensely fast, once power is cut, everything is forgotten! On the other hand, your traditional hard drive or SSD (Solid State Drive) stores gigabytes of documents, but it’s considerably slower than DRAM. Intel and Micron have recently released their new technology, the 3D XPoint, which sits between these existing technologies. It is said to be 1000 times faster than SSD and 10 times denser than DRAM. It is also non-volatile, which means there’s no need to power it.


Memory Modules


What is it? A circuit board with a specific amount of DRAM chips mounted on them. They are used in laptops, PCs, and servers. These modules will generally have 8, 16, or 32 DRAM chips on it if it is a non-parity board. A parity board has an extra chip for each 8 DRAM chips, for the purpose of improving the buffering and ECC (error-correcting code) correction.

Types of modules:

  • Unbuffered DIMMs: The basic board that has 8, 16, or 32 DRAM chips, and is cost effective. There is no control among the chips. Therefore, the chips collect data at anytime, even in the middle of a clock cycle. This results in the module less efficient when it comes to reading data.

  • Fully buffered DIMMs: Found on DDR2 boards only. Includes both a parity chip as well as an AMB chip (Advanced Memory Buffer). This provides a buffer between the controller and the module, which can improve the timing for the clock cycle.

  • Registered DIMMs: The most popular module, it provides a delay so that all data is collected at the beginning and end of the clock cycles, which greatly improves the performance of the module. It includes a parity chip and is found on all SDR and DDR modules that are used for server applications.

  • Small Outline DIMMs: Any of the above in a smaller version

Major Producers: Micron, Hynix, and Samsung


News of Today: Micron has recently worked with Freescale Semiconductor to create a single chip module (SCM) solution that spans across many applications that are looking to reduce physical size and complexity. Samsung, another big player with modules, has recently started mass production of the industry’s first 32-gigabyte registered dual in-line module, which will be manufactured based on a new 20-nanometer process technology, to use in enterprise servers. The new module’s data transfer rate per pin reaches up to 2,400 megabits per second, which delivers an approximately 29% increase in performance.