There are several types of memory, what is the current mainstream, what is DDR, DDR2

This form factor is available on the RIMM Dual Inline 8088, 8086, 286.

SIMM Single Inline 286, 386, 486 are available in this form.

edo sdram

rdramddr sdram

ddr2 sdram

DDR2 memory is now the mainstream in the market.

1. DDR is a memory technology produced after SDRAM, DDR, which originally means "doubledatarate" in English, as the name suggests, is a dual data transmission mode. The reason why it is called "double" means that there is "single", the SDRAM we use daily is "single data transmission mode", the characteristic of this memory is to perform an operation (read or write) on the rising edge of a square wave in a memory clock cycle, and DDR refers to a new design, which operates once on the rising edge of the square wave in a memory clock cycle, and also does an operation on the falling edge of the square wave. DDR can complete the task that can only be completed by two cycles of SDRAM, so theoretically, the performance of DDR memory at the same rate is more than double that of SDR memory, which can be simply understood as 100MHz DDR=200MHz SDR.

Details of the DDR:

2, DDR2 (Double Data Rate 2) SDRAM is a new generation of memory technology standard developed by JEDEC (Joint Committee on Electronic Equipment Engineering), the biggest difference between it and the previous generation DDR memory technology standard is that although it adopts the basic way of data transmission at the same time as the rise and fall of the clock, DDR2 memory has twice the pre-read ability of the previous generation DDR memory (i.e., 4-bit data read pre-fetching). In other words, DDR2 memory is capable of reading and writing data at 4 times the speed of the external bus per clock, and can run at 4 times the speed of the internal control bus.

The memory that has been eliminated and the SD Edo RD are all discontinued, except for the SD (Ben 3 machine) in the world!

DDR3 writes will be faster. The difference used to be huge, but now it's much smaller. Pay attention to the compatibility of the motherboard.

DDR2 is the 2nd generation DDR3 and 3rd generation of course, the latter has higher performance.

It's a comparison of video memory, D3 has one more grain than D2, and opens the same number of programs, relatively speaking, D3 is not so stuck. That's what it means.

The difference between the types of memory modules is essentially the difference in speed, and the newer the type of memory, the faster the speed.

Then, in order to ensure that there is no misinsertion, the physical slots are also different.

The graph below is a comparison of the different appearances of the three generations of DDR memory.

1. DDR1 generation, up to 533.

2. DDR2 generation, up to 1066.

3. DDR3 generation, up to about 2400.

4. DDR4 generation, starting from 2400.

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