YEAR INTRODUCED TECHNOLOGY SPEED LIMIT
1987 FPM 50ns
1995 EDO 50ns
1997 PC66 SDRAM 66MHz
1998 PC100 SDRAM 100MHz
1999 RDRAM 800MHz
1999/2000 PC133 SRAM 133MHz (VCM option)
2000 DDR SDRAM 266MHz
2001 DDR SDRAM 333MHz
2002 DDR SDRAM 434MHz
2003 DDR SDRAM 500MHz
2004 DDR2 SDRAM 533MHz
2005 DDR2 SDRAM 800MHz
2006 DDR2 SDRAM 667 – 800MHz
2007 DDR3 SDRAM 1066 – 1333MHz
2012 DDR4 ….
FPM – EDO
72-Pin SIMM 100-Pin DIMM
SDRAM
168-Pin DIMM
PC-66
PC-100
PC-133
RDRAM
184 pins
PC800 Rambus RIMM (RDRAM) – 184 pins
PC1066 Rambus RIMM (RDRAM) – 184 pins
PC1200 Rambus RIMM (RDRAM) – 184 pins
Memory Name Frequency (RAM) Frequency (FSB) Speed
184-Pin DIMM
DDR200 PC1600 200 MHz 100 MHz 1.6 Go/s
DDR266 PC2100 266 MHz 133 MHz 2.1 Go/s
DDR333 PC2700 333 MHz 166 MHz 2.7 Go/s
DDR400 PC3200 400 MHz 200 MHz 3.2 Go/s
DDR433 PC3500 433 MHz 217 MHz 3.5 Go/s
DDR466 PC3700 466 MHz 233 MHz 3.7 Go/s
DDR500 PC4000 500 MHz 250 MHz 4 Go/s
DDR533 PC4200 533 MHz 266 MHz 4.2 Go/s
DDR538 PC4300 538 MHz 269 MHz 4.3 Go/s
DDR550 PC4400 550 MHz 275 MHz 4.4 Go/s
Form Factor: 240-Pin DIMM
DDR2-400 PC2-3200 400 MHz 100 MHz 3.2 Go/s
DDR2-533 PC2-4300 533 MHz 133 MHz 4.3 Go/s
DDR2-667 PC2-5300 667 MHz 167 MHz 5.3 Go/s
DDR2-675 PC2-5400 675 MHz 172.5 MHz 5.4 Go/s
DDR2-800 PC2-6400 800 MHz 200 MHz 6.4 Go/s
DDR2 PC2-4200 533MHz 266MHz
DDR2 PC2-5400 667MHz 333MHz
DDR2 PC2-6000 750MHz 375MHz
DDR2 PC2-6400 800MHz 400MHz
DDR2 PC2-8000 1000MHz 500MHz
DDR2 PC2-8800 1100MHz 550MHz
DDR2 PC2-9000 1120MHz 560MHz
Form Factor: 240-Pin DIMM
DDR3 PC3-6400 800MHz 400MHz
DDR3 PC3-8500 1066MHz 533MHz
DDR3 PC3-10666 1333MHz 667MHz
DDR3 PC3-12800 1600MHz 800MHz
DDR3 PC3-14400 1800MHz 900MHz
DDR3 PC3-16000 2000MHz 1000MHz
DDR4
Coming 2012
Check
http://www.memory.com/
MAJOR CHIP TECHNOLOGIES
It’s usually pretty easy to tell memory module form factors apart because of physical differences. Most module form factors can support various memory technologies so, it’s possible for two modules to appear to be the same when, in fact, they’re not. For example, a 168-pin DIMM can be used for EDO, Synchronous DRAM, or some other type of memory. The only way to tell precisely what kind of memory a module contains is to interpret the marking on the chips. Each DRAM chip manufacturer has different markings and part numbers to identify the chip technology.
FAST PAGE MODE (FPM)
At one time, FPM was the most common form of DRAM found in computers. In fact, it was so common that people simply called it “DRAM,” leaving off the “FPM”. FPM offered an advantage over earlier memory technologies because it enabled faster access to data located within the same row.
EXTENDED DATA OUT (EDO)
In 1995, EDO became the next memory innovation. It was similar to FPM, but with a slight modification that allowed consecutive memory accesses to occur much faster. This meant the memory controller could save time by cutting out a few steps in the addressing process. EDO enabled the CPU to access memory 10 to 15% faster than with FPM.
SYNCHRONOUS DRAM (SDRAM)
In late 1996, SDRAM began to appear in systems. Unlike previous technologies, SDRAM is designed to synchronize itself with the timing of the CPU. This enables the memory controller to know the exact clock cycle when the requested data will be ready, so the CPU no longer has to wait between memory accesses. SDRAM chips also take advantage of interleaving and burst mode functions, which make memory retrieval even faster. SDRAM modules come in several different speeds so as to synchronize to the clock speeds of the systems they’ll be used in. For example, PC66 SDRAM runs at 66MHz, PC100 SDRAM runs at 100MHz, PC133 SDRAM runs at 133MHz, and so on. Faster SDRAM speeds such as 200MHz and 266MHz are currently in development.
DOUBLE DATA RATE SYNCHRONOUS DRAM (DDR SDRAM)
DDR SDRAM, is a next-generation SDRAM technology. It allows the memory chip to perform transactions on both the rising and falling edges of the clock cycle. For example, with DDR SDRAM, a 100 or 133MHz memory bus clock rate yields an effective data rate of 200MHz or 266MHz. Click here for more on DDR. Click here for more on DDR.
DOUBLE DATA RATE 2 SYNCHRONOUS DRAM (DDR2 SDRAM)
DDR2 is the second generation of Double Data Rate (DDR) SDRAM memory. It is an evolution of DDR memory technology that delivers higher speeds (up to 800 MHz), lower power consumption and heat dissipation. It is an ideal memory solution for bandwidth hungry systems and the lower power consumption is a perfect match for today’s mobile users. Click here for more on DDR2.
DOUBLE DATA RATE 3 SYNCHRONOUS DRAM (DDR3 SDRAM)
DDR3 is the third generation of Double Data Rate (DDR) SDRAM memory. Similar to DDR2, it is a continuing evolution of DDR memory technology that delivers higher speeds (up to 1600 MHz), lower power consumption and heat dissipation. It is an ideal memory solution for bandwidth hungry systems equipped with dual and quad core processors and the lower power consumption is a perfect match for both server and mobile platforms. DDR3 modules available in the second half of 2007.
DIRECT RAMBUS
Direct Rambus is a DRAM architecture and interface standard that challenges traditional main memory designs. Direct Rambus technology is extraordinarily fast compared to older memory technologies. It transfers data at speeds up to 800MHz over a narrow 16-bit bus called a Direct Rambus Channel. This high-speed clock rate is possible due to a feature called “double clocked,” which allows operations to occur on both the rising and falling edges of the clock cycle. Also, each memory device on an RDRAM module provides up to 1.6 gigabytes per second of bandwidth – twice the bandwidth available with current 100MHz SDRAM. – http://www.kingston.com/tools/umg/umg05a.asp
WTJR Engineering 