SDRAM

(redirected from Dual channel DDR)

SDRAM

[¦es¦dē′ram]

SDRAM

SDRAM

(Synchronous DRAM) The type of dynamic RAM memory chip that has been widely used since the mid-1990s. SDRAM eliminated wait states by dividing the chip into two cell blocks and interleaving data between them. While a bit in one block is accessed, a bit in the other is prepared for access. See dynamic RAM.

DDR (Double Data Rate)
In 2000, DDR SDRAM doubled the data transfer rate by using both the rising and falling edges of the clock cycle. The data rate of each DDR generation is faster than the previous with a six-fold increase from DDR1 to DDR4. In addition, less power is required (see table below). In order to prevent inserting the wrong DDR into the motherboard, DDR memory modules are keyed differently (for details, see memory module).

Channels
Chipsets on the motherboard may support one, two or four memory channels (triple channel has since come and gone). For example, mainstream motherboards support dual channel, which is why memory modules are generally installed in pairs. While data are being read or written to one memory module, the second module is being prepared for reading or writing. High-end motherboards support quad channel. Following are the most popular module speeds for each SDRAM generation. See GDDR.

        Clock    Transfer        DIMM        Speed      Rate         Module DDR    (MHz)     (MT/s)    (V)  Pins

 DDR5 1600-3200  3200-6400  1.1  288
 DDR4  800-1600  1600-3200  1.2  284
 DDR3  400-1200   800-2400  1.5  240
 DDR2  200-533    533-800   1.8  240
 DDR   100-200    200-400   2.5  184
 SDRAM  66-133     66-133   3.3  168


Matched Slots for Dual Channel
This motherboard uses colored sockets so that module pairs are inserted properly. It supports three pairs (one orange and two lavender). (Image courtesy of Giga-byte Technology Company Ltd., www.giga-byte.com)







A Little Nostalgia
These 12 bits of magnetic core memory from the Whirlwind computer of the early 1950s take up about a quarter of a square inch. Today, that much space holds billions of bits. (Image courtesy of The MITRE Corporation Archives.)
References in periodicals archive ?
Fremont, CA, February 18, 2011 --(PR.com)-- Newest Intro Designed for Rugged Environments; Includes Large 15.6" Display with HD Resolution, Intel[R] Compliant HD Stereo Audio, and Two Dual Channel DDR III Memory Slots
In addition, the VGA port supports two PCI Express x 16 Video Cards, and has a memory capacity up to 4 GB of 266/333/400 MHZ Dual Channel DDR SDRAM.
SOPORTE DE MEMORIA (SLOTS): Dos de 184 pines Dual Channel DDR 400
"Extensive hardware and software testing, along with proven technology including a compelling dual channel DDR memory interface and dual VGA-monitor capability, ensures IT buyers and business users of a compatible and reliable platform."
The first release is the IntelliStation M Pro 6219 which features a choice of graphics accelerator, up to 4.0GB dual channel DDR memory, front-mounted USB 2.0 ports, an Intel Pentium 4 processor up to 3.06GHz, 533MHz system bus, 8X AGP graphics, Ultra320 SCSI and integrated Gigabit Ethernet.
The ePCI-201 includes a set of standard features including the latest generation Intel[R] Pentium[R]4 processor up to 3.4 GHz, up to 800 MHz front side bus, dual channel DDR memory, two-channel serial ATA, on-board ATI[R] Mobility[TM] Radeon[TM] M7 or M9 video controller, dual Gigabit Ethernet and 64-bit at 66 MHz bus support.
Tres ranuras DIMM de 184 pines, soporta hasta 3GB de memoria Dual Channel DDR 200/266/333MHz, tres ranuras PCI, ranura AGP 8X/4X, chipset NVIDIA nForce2 IGP / MCP, video integrado NVIDIA GeForce4 MX GPU con hasta 128MB, audio integrado de seis canales, adaptador LAN integrado, factor de forma Micro ATX, soporta cuatro dispositivos IDE Ultra DMA 33/66/100/133MHz Biostar P4VTB/800.
edition(64 Bit) operating system and suitable Main board - Intel H87 chipset or higher supporting dual channel DDR 3