Difference between revisions of "random access memory/types"

Revision as of 17:44, 28 June 2021

SDRAM = "Synchronous Dynamic Random Access Memory", meaning that they use a clock signal to synchronize things
DDR = "Double Data Rate", meaning that they transfer two data chunks per clock cycle

Technology	Typical Voltage	Typical Latency	Other Common Latencies Available	Data Path
DDR	2.5 V	3	2, 2.5	2 bits
DDR2	1.8 V	5	3, 4	4 bits
DDR3	1.5 V	7	6, 8, 9	8 bits

Chip Tech/Speed	Real Clock	MTRR	Module Tech/Speed
DDR-200	100 MHz	1,600 MB/s	PC-1600
DDR-266	133 MHz	2,133 MB/s	PC-2100
DDR-333	166 MHz	2,666 MB/s	PC-2700
DDR-400	200 MHz	3,200 MB/s	PC-3200
DDR2-400	200 MHz	3,200 MB/s	PC2-3200
DDR2-533	266 MHz	4,266 MB/s	PC2-4200
DDR2-667	333 MHz	5,333 MB/s	PC2-5300
DDR2-800	400 MHz	6,400 MB/s	PC2-6400
DDR2-1066	533 MHz	8,533 MB/s	PC2-8500
DDR3-800	400 MHz	6,400 MB/s	PC3-6400
DDR3-1066	533 MHz	8,500 MB/s	PC3-8500
DDR3-1333	666 MHz	10,666 MB/s	PC3-10600
DDR3-1600	800 MHz	12,800 MB/s	PC3-12800

For DDR RAM, the real clock rate is always half the rated transfer speed. The module speed is in bytes/second.

@@ Line 2: / Line 2: @@
 * '''SDRAM''' = "Synchronous Dynamic Random Access Memory", meaning that they use a clock signal to synchronize things
 * '''DDR''' = "Double Data Rate", meaning that they transfer two data chunks per clock cycle
-==Voltage==
+==Technologies==
 {| border=1
 |-
-! Technology !!	Typical Voltage
+! Technology !!	Typical Voltage !! Typical Latency !! Other Common Latencies Available || Data Path
 |-
-| DDR || 2.5 V
+| DDR || 2.5 V || 3 || 2, 2.5 || 2 bits
 |-
-| DDR2 || 1.8 V
+| DDR2 || 1.8 V || 5 || 3, 4  || 4 bits
 |-
-| DDR3 || 1.5 V
+| DDR3 || 1.5 V || 7 || 6, 8, 9 || 8 bits
 |}
 ==Speed==