MEMORY FAQs
What are the different formats of memory modules?
DIMM (Dual Inline Memory Module) For use in most desktops and printers.
SODIMM (Small Outline DIMM) For use in most notebooks and few printers.
MicroDIMM For use in some ultra portable notebooks. Smaller than SODIMMs.
SIMM (Single Inline Memory Module) Obsolete, was used in many desktops and printers.
RIMM RIMM is a trademarked name for a Direct Rambus module. It was used in some Pentium 3 and Pentium 4 machines.
What are the different memory technologies?
DDR2 (Double Data Rate 2) The most recent version of DDR memory. It is capable of running at speeds up to 800MHz. Used in Pentium 4 class PCs.
DDR or DDR1 (Double Data Rate) The first version of DDR SDRAM memory. It is a kind of SDRAM memory. It is capable of running at twice the speed of its predecessor SDRAM memory. Used in Pentium 4 class PCs.
SDRAM (Synchronous Dynamic Random Access Memory) The first kind of memory technology that synchronized itself with the CPU clock to reduce wait times. Used in many Pentium, Pentium II, Pentium 3 and Pentium 4 class PCs.
Direct RAMBUS Used in some Pentium III and Pentium 4 based computers.
EDO (Extended Data Output) A faster version of FPM memory.
FPM (Fast Page Mode) The earliest type of DRAM memory.
What are the different pin counts for memory modules?
240 pin DIMM This DIMM is used for DDR2 memory modules.
200 pin SODIMM This SODIMM type is used for DDR2 and DDR(DDR1) memory modules.
184 pin DIMM This DIMM is used for DDR(DDR1) memory modules.
168 pin DIMM This DIMM is used for SDRAM, EDO and FPM memory modules.
144 pin SODIMM This SODIMM is used for SDRAM and EDO memory modules.
72 pin SIMM This SIMM is used for FPM and EDO memory modules.
72 pin SODIMM This SODIMM is used for FPM and EDO memory modules.
What are the different speeds of memory modules?
DDR2 Memory is available in following speeds:
PC2-8000/1000MHz, PC2-6400/800MHz, PC2-5300/667MHz, PC2-4200/533MHz, PC2-3200/400MHz.
DDR or DDR1 Memory is available in following speeds:
PC3200/400MHz, PC2700/333MHz, PC2100/266MHz, PC1600/200MHz.
SDRAM Memory is available in the following speeds:
PC133/133MHz, PC100/100MHz, PC66/66MHz
EDO Memory is available in the following speeds:
50 nanoseconds, 60 nanoseconds, 70 nanoseconds
FPM Memory is available in the following speeds:
60 nanoseconds, 70 nanoseconds, 80 nanoseconds
What is ECC and Parity Memory?
ECC (Error Correction Code) and Parity memory modules have an extra memory chip for every eight memory chips on the module. The extra chip acts as a data integrity check. This kind of memory is required only for high end servers and workstations. Most other desktops and all notebooks have an alternate and cheaper data integrity check built into the memory controller.
What is Registered and Buffered Memory?
Registers and buffers are special chips used to control electrical signals to the memory module. Memory modules with registers or buffers are usually ECC memory modules used in high end servers and workstations. They do not work in standard desktops which require UnBuffered/Non-registered memory.
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