EddyHawk's Info List
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MEMORY MODULE
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-S(tatic)RAM
 uses bipolar transistor & TTL (Transistor-Transistor Logic) tech
 10x faster (practically 3x faster) but low density (larger than DRAM module)
 known speed: 4ns
 now is used as mcpu's L1/L2 on-die cache, several types are:
  (dual bank) pipelined burst, (a)synchronous

-D(ynamic)RAM
 uses CMOS tech
 high-density but slower than SRAM because its content must be periodically
  refreshed electrically

 SPM (Slow Page Mode (?))

 FPM (Fast Page Mode)
  25Mhz

 EDO (Extended Data Out)
  simultaneous data access (not wait finish of previous access)
  3% faster than DRAM
  note: EDO & SDRAM can't be mixed

 BEDO (Burst EDO)

 S(ynchronous)DRAM
  64bit or 8b wide
  > 100Mhz, burst, 2 banks, mode reg.
  uses external clock pulse called pixel clock
  3.3V, 168 pins
  note:
   send data at beginning edge of clock cycle
   EDO & SDRAM can't be mixed
  known speed:
   PC100 = 100Mhz x 8b ~ 800Mb/sec
    10ns
    8ns
   PC133 = 133Mhz x 8b ~ 1,066Mb/sec
    7.5ns
    60ns ?
    70ns ?
    CAS2: 2 clocks CAS latency, better than CAS3
    CAS3: 3 clocks CAS latency
   PC1##: Intel open specification

  DDR (Double Data Rate) SDRAM
  note: send data at beginning & ending edge of clock cycle
  2.5V, 184 pins
  known speed:
   PC100 DDR or PC200 or PC1600 = 100Mhz x 2 (DDR) x 8b = 1,600Mb/sec
   PC133 DDR or PC266 or PC2100 = 133Mhz x 2 (DDR) x 8b = 2,133Mb/sec
    266A: CL 2
    266B: CL 2.5
   PC166 DDR or PC333 or PC2700 = 166Mhz x 2 (DDR) x 8b = 2,666Mb/sec
  note:
   nVIDIA releases n'Force chipset utilizing dual DDR-SDRAM PC266 for Athlon/Duron mcpu, raise speed to 2 x 2,133Mb/sec = 4.2Gb/sec
   PC1600/PC2100 is JEDEC specification

  DDR-SDRAM II
  by: JEDEC (?)
  EdH: it better be called QDR (Quad Data Rate)

  QBM (Quad Band Memory)
  by: Kentron Technologies
  note: not memory module

  B(Bi-directionally strobbed or Burst)DDR-SDRAM
  BDDR-SDRAM II

  VC (Virtual Channel) SDRAM

-RD(Rambus Direct/Dynamic)RAM
 by: Rambus
 16bit wide serial bus running at DDR-ed 300/400Mhz
 adv: highest clock
 known speed:
  PC600: 266Mhz * 2 (DDR) * 2b (width) = 1.066 Gb/sec (same bandwidth as PC133 SDRAM)
  PC700: 356Mhz * 2 (DDR) * 2b (width) = 1.4Gb/sec
  PC800: 400Mhz * 2 (DDR) * 2b (width) = 1.6Gb/sec
 disadv:
  narrow width
  very expensive
  low yields (of PC800)
  royalty
  high latencies
   note: Intel overcome this with dual channel for PIII/P 4, which also raises speed to 3.2Gb/sec

-V(ideo)RAM
 type: gfx mem
 dual port: RAM, SAM

-W(indow)RAM
 type: gfx mem
 extended VRAM

-SG(Synchronous Graphic)RAM
 type: gfx mem
 SDRAM with gfx extension, for video card mem

-M(ultibank)DRAM
 64kb block