* SDR SDRAM: Single Data Rate Synchronous Dynamic Random Access Memory

-         introduced in year 1997

-         Pins: 168

-         Operating voltage: 3.3 V

-         clock speeds are 66, 100, and 133 MHz (15, 10, and 7.5 ns/cycle)

-         ECC, non-ECC

 

* DRDRAM: Direct Rambus Dynamic Random Access Memory, or, RDRAM: Rambus DRAM

-         The motherboards with support for RDRAM debuted in 1999

-         Pins: 184

   Stick/module specification

·     PC600: 16-bit, single channel RIMM, operate at 300 MHz clock speed, 1200 MB/s bandwidth

·     PC700: 16-bit, single channel RIMM, operate at 355 MHz clock speed, 1420 MB/s bandwidth

·     PC800: 16-bit, single channel RIMM, operate at 400 MHz clock speed, 1600 MB/s bandwidth

·     PC1066 (RIMM 2100): 16-bit, single channel RIMM, 533 MHz clock speed, 2133 MB/s bandwidth

·     PC1200 (RIMM 2400): 16-bit, single channel RIMM, 600 MHz clock speed, 2400 MB/s bandwidth

·     RIMM 3200: 32-bit, dual channel RIMM, operate at 400 MHz clock speed, 3200 MB/s bandwidth

·     RIMM 4200: 32-bit, dual channel RIMM, operate at 533 MHz clock speed, 4200 MB/s bandwidth

·     RIMM 4800: 32-bit, dual channel RIMM, operate at 600 MHz clock speed, 4800 MB/s bandwidth

·     RIMM 6400: 32-bit, dual channel RIMM, operate at 800 MHz clock speed, 6400 MB/s bandwidth

* DDR SDRAM: Double Data Rate Synchronous Dynamic Random Access Memory

-         introduced in year 2000

-         Pins: 184

-         Operating voltage: 2.5 V

-         are not backwards compatible with SDR SDRAM

-         ECC, non-ECC, Registered (Buffered), non-Registered (unbuffered)

   Spec standards (Chips/Modules)

Standard name

(Chip Type)

Module name

Memory clock

I/O Bus clock

Data transfers

Per second

Peak transfer rate

(Bandwidth)

DDR-200

PC2-1600

100 MHz

200 MHz

200 Million

1.600 GB/s

DDR-266

PC2-2100

133 MHz

266 MHz

266 Million

2.133 GB/s

DDR-333

PC2-2700

166 MHz

333 MHz

333 Million

2.667 GB/s

DDR-400

PC2-3200

200 MHz

400 MHz

400 Million

3.200 GB/s

 

 

* DDR2 SDRAM: Double Data Rate Two Synchronous Dynamic Random Access Memory

-         introduced in the second quarter of 2003

-         Pins: 240

-         Operating voltage: 1.8 V

-         are not backwards compatible with DDR DIMMs

-         ECC, non-ECC, Registered (Buffered), non-Registered (unbuffered)

     Spec standards (Chips/Modules)

Standard name

(Chip Type)

Module name

Memory clock

I/O Bus clock

Data transfers

Per second

Peak transfer rate

(Bandwidth)

DDR2-400

PC2-3200

100 MHz

200 MHz

400 Million

3.200 GB/s

DDR2-533

PC2-4200

133 MHz

266 MHz

533 Million

4.264 GB/s

DDR2-667

PC2-5300

166 MHz

333 MHz

667 Million

5.336 GB/s

DDR2-800

PC2-6400

200 MHz

400 MHz

800 Million

6.400 GB/s

DDR2-1066

(planned)

PC2-8500

(planned)

266 MHz

533 MHz

1066 Million

8.500 GB/s

Note: DDR2-xxx (or DDR-xxx) denotes effective clockspeed, whereas PC2-xxxx (or PC-xxxx) denotes theoretical bandwidth (though it is often rounded up or down). Bandwidth is calculated by taking transfers per second and multiplying by eight

 

* DDR3 SDRAM: Double Data Rate Three Synchronous Dynamic Random Access Memory

 

-         announced in early 2005, while the specification is expected to be publicly available in mid-2007.

-         Pins: 240

-         Operating voltage: 1.5 V

-         are not backwards compatible with DDR2 DIMMs

   Spec standards (Chips/Modules)

Standard name

(Chip Type)

Module name

Memory clock

I/O Bus clock

Data transfers

per second

Peak transfer rate

(Bandwidth)

DDR3-800

PC3-6400

100 MHz

400 MHz

800 Million

6.40 GB/s

DDR3-1066

PC3-8500

133 MHz

533 MHz

1066 Million

8.53 GB/s

DDR3-1333

PC3-10600

166 MHz

667 MHz

1333 Million

10.67 GB/s

DDR3-1600

PC3-12800

200 MHz

800 MHz

1600 Million

12.80 GB/s