Pengertian Memory Pada PC

Kadang kita bingung membedakan Ram DDR1, DDR2 dan DDR3. Gimana  sistem perhitungan clocknya dan kelas-kelasnya. 

Dengan DDR dan clocknya, berikut ini saya tampilkan tabel clock dan transfer ratenya. Semoga bermanfaat.

DDR1:

• DDR-200 = PC-1600
• DDR-266 = PC-2100
• DDR-333 = PC-2700
• DDR-400 = PC-3200

DDR2:

• DDR2-400 = PC2-3200
• DDR2-533 = PC2-4200
• DDR2-667 = PC2-5300
• DDR2-800 = PC2-6400
• DDR2-1066= PC2-8500

DDR3:

• DDR3-800 = PC3-6400
• DDR3-1066 = PC3-8500
• DDR3-1333 = PC3-10600
• DDR3-1600 = PC3-12800
• DDR3-1866 = PC3-14900
• DDR3-2133 = PC3-17000

Keterangan tabel detailnya adalah sebagai berikut ini:

Std Nm= Standard Name

Mem Clk= Memory clock(MHz)

Cy Tm= Cycle time[4](ns)

Bus Clk= I/O bus clock(MHz)

Dt Rt= Data rate(MT/s)

Volt= VDDQ(V)

Mod Nm= Module name

PTR= Peak transfer rate(MB/s)

Tim= Timings

CAS Lat= CAS latency(ns)

DDR1:

Std Nm	Mem Clk	Cy Tm	Bus Clk	Dt Rt	Volt	Mod Nm	PTR	Tim
DDR-200	100	10	100	200	2.5±0.2	PC-1600	1600
DDR-266	133?	7.5	133?	266?		PC-2100	2133?
DDR-333	166?	6	166?	333?		PC-2700	2666?
DDR-400A DDR-400B DDR-400C	200	5	200	400	2.6±0.1	PC-3200	3200	2.5-3-3 3-3-3 3-4-4

DDR2:

Std Nm	Mem Clk	Cy Tm	Bus Clk	Dt Rt	Md Nm	Peak transfer rate(MB/s)	Tim	CAS Lat
DDR2-400B DDR2-400C	100	10	200	400	PC2-3200	3200	3-3-3 4-4-4	15 20
DDR2-533B DDR2-533C	133?	7½	266?	533?	PC2-4200*	4266?	3-3-3 4-4-4	11¼ 15
DDR2-667C DDR2-667D	166?	6	333?	666?	PC2-5300*	5333?	4-4-4 5-5-5	12 15
DDR2-800C DDR2-800D DDR2-800E	200	5	400	800	PC2-6400	6400	4-4-4 5-5-5 6-6-6	10 12½ 15
DDR2-1066E DDR2-1066F	266?	3¾	533?	1066?	PC2-8500*	8533?	6-6-6 7-7-7	11¼ 13?

DDR3:

Std Nm	Mem Clk	Cy Tm	Bus Clk	Dt Rt	Mod Nm	PTR	Tim	CAS lat
DDR3-800D DDR3-800E	100	10	400	800	PC3-6400	6400	5-5-5 6-6-6	12 1?2 15
DDR3-1066E DDR3-1066F DDR3-1066G	133?	7 1?2	533?	1066?	PC3-8500	8533?	6-6-6 7-7-7 8-8-8	11 1?4 13 1?8 15
DDR3-1333F* DDR3-1333G DDR3-1333H DDR3-1333J*	166?	6	666?	1333?	PC3-10600	10666?	7-7-7 8-8-8 9-9-9 10-10-10	10 1?2 12 13 1?2 15
DDR3-1600G* DDR3-1600H DDR3-1600J DDR3-1600K	200	5	800	1600	PC3-12800	12800	8-8-8 9-9-9 10-10-10 11-11-11	10 11 1?4 12 1?2 13 3?4
DDR3-1866J* DDR3-1866K DDR3-1866L DDR3-1866M*	233?	4 2?7	933?	1866?	PC3-14900	14933?	10-10-10 11-11-11 12-12-12 13-13-13	10 5?7 11 11?14 12 6?7 13 13?14
DDR3-2133K* DDR3-2133L DDR3-2133M DDR3-2133N*	266?	3 3?4	1066?	2133?	PC3-17000	17066?	11-11-11 12-12-12 13-13-13 14-14-14	10 5?16 11 1?4 12 3?16 13 1?8

* optional

• CL – Clock cycles between sending a column address to the memory and the beginning of the data in response
• tRCD – Clock cycles between row activate and reads/writes
• tRP – Clock cycles between row precharge and activate
• Fractional frequencies are normally rounded down, but rounding up to -667 is common due to superstition about the number 666.
• ……DDR3 SDRAM:….Double Data Rate SDRAM III (Quad Edge ‘Clock’ Rate, 1.5v signaling), Third Generation
• ………PC3-6400 (DDR3-800 SDRAM); Clock Speed: 100MHz, Data Rate: 800MHz, Through-put 6.40GB/s
• ………PC3-8500 (DDR3-1066 SDRAM); Clock Speed: 133MHz, Data Rate: 1066MHz, Through-put 8.53GB/s
• ………PC3-10600 (DDR3-1333 SDRAM); Clock Speed: 166MHz, Data Rate: 1333MHz, Through-put 10.67GB/s
• ………PC3-12800 (DDR3-1600 SDRAM); Clock Speed: 200MHz, Data Rate: 1600MHz, Through-put 12.80GB/s

source:

http://en.wikipedia.org/wiki/DDR1_SDRAM

http://en.wikipedia.org/wiki/DDR2_SDRAM

http://en.wikipedia.org/wiki/Ddr3

http://www.interfacebus.com/Memory_Module_DDR3_DIMM.html