Rookie learn the second diagram of installed memory installation

After installing the CPU, the next step is to start installing the memory strips. Before installing the memory strips, you can check the motherboard specification for the type of memory that the motherboard can support, the slot data that can be installed on the memory, the maximum supported capacity, and so on. Although these are simple, do you know how different memory strips are differentiated? Do you know why EDO RAM memory must be in pairs to be used? Do you know why the free location of the Rdram memory slots is filled with finalizers to use? These are all things that you must know to install the memory strips. If you do not know, then this article is very suitable for you.

First, recognize the memory from the appearance

Since the birth of the computer, the development of memory pattern is really changeable. Therefore, the following first focus on the type of memory and its appearance, so that we can distinguish them, this is the installation process we must understand. In memory mode, common memory is: FPM RAM, EDO RAM, SDRAM, DDR Ram, Rambus DRAM, as shown in Figure 1. From the outward appearance, the difference between them is mainly the length and the number of pins, as well as the corresponding gap on the pin.

FPM Ram was popular in the 286, 386 era, when it used 30pin FPM RAM memory with a capacity of only 1MB or 2MB. And in the 486 era, and a few 586 computers also use 72pin of FPM RAM memory. EDO RAM is mainly used in 486, 586 times, also has 72pin and 168pin points. In terms of appearance, 30pin of FPM RAM memory is the shortest, 72pin FPM RAM and Edo RAM memory is slightly longer, while 168pin and Edo RAM memory is basically the same as common SDRAM memory. These types of memory can easily be separated from the length and number of pins. But the memory has largely vanished.

Tip: Because the memory data width of Edo RAM and FPM RAM is 32 bits, the data bus width of Pentium and above level is 64 bits. Therefore, to use these memory bars in the Pentium and above-level computers, you must use two identical memory strips at the same time. The pair of two memory strips is best to use the same model, and the same amount of memory.

The most common SDRAM memory you have is 168 pins with two asymmetric notches on the pin. On both sides of the SDRAM memory, you can also find that each has a notch. If it is pc100/133 SDRAM, it will include a 8-pin SPD chip on the memory strip, which is a necessary and important symbol for identifying pc100/133 memory. But we also have to note that there is a SPD chip does not necessarily represent this SDRAM memory is pc100/133, but if not it is certainly not.
Next, let's look at how the DDR RAM differs from SDRAM. In terms of appearance, DDR RAM differs from conventional SDRAM in that they have the same total length as their golden fingers. However, the DDR RAM memory has 184 pins, and there is only one small notch on the pin. In addition, there are two gaps on both sides of the DDR RAM memory. The
Rambus DRAM (also known as RDRAM) memory has the same pin as the DDR RAM memory, with 184 pins. But it looks completely different from SDRAM and DDR RAM. The first choice is to wrap a metal shield over the outside of the rdram to reduce electromagnetic interference. Attention to its pins, in the middle of the two notches near the design pin, these two gaps and SDRAM on the two gap is not the same OH. On both sides of the rdram memory, there is a gap.

Small knowledge: Simms, DIMMs, RIMM
Different memory strips must be installed on a dedicated memory slot on the motherboard. The main memory slots applied to desktop computers are: Simms, DIMMs, and RIMM, which are listed on the motherboard's memory slot and on the motherboard specification.
Simms (Single In-line Memory module, one-sided contact memory module) is a common memory slot in 486 and its older PCs. Simms There are two main types of memory slots: 30pin and 72pin. 30pin single-sided memory bar is used to support 8-bit data processing volume. 72pin single-sided memory bar is used to support 32-bit data processing volume. So, for example, you can handle the 64-bit Intel Pentium Series CPU at one time, and you need 8 or 2 72pin of memory chips to support it. Before 486, most of them used 30pin of Simms slots, or with 72pin of Simms slot, while in Pentium, the application is more 72pin Simms interface, or with DIMM slots.
DIMM (Dual in-line Memory module, bilateral contact memory module) memory slot refers to both sides of this type of interface memory have data interface contacts, this interface mode of memory is usually 84pin or 92pin, but because it is bilateral, so there are 84x2= 168pin or 92x2=184pin contact. DIMM Memory Slots Support 64-bit data transfer with 3.3V voltage.
The RIMM (Rambus in-line Memory Module) memory slot is the slot that supports the direct RDRAM memory bar. RIMM has 184pin, data output mode is serial, with the existing DIMM module 168pin, parallel output of the architecture is very different.