What are the types of memory slots? What is a memory module?

One, memory slot

Memory slot refers to the type and number of memory slots used on the motherboard. The type and capacity of memory supported by the motherboard are determined by the memory slot. At present, the memory slots mainly used on the motherboard are:

1.SIMM(Single Inline Memory Module)

168-pin SIMM slot

The memory module is connected to the mainboard through gold fingers. The front and back sides of the memory module are equipped with gold fingers. Goldfingers can provide different signals on both sides, or they can provide the same signal. SIMM is a kind of memory structure on both sides of the gold finger to provide the same signal, it is mostly used in the early FPM and EDD DRAM, initially can only transmit 8bif data, and later gradually developed 16bit, 32bit SIMM module, of which 8bit and 16bitSIMM use 30pin interface. The 32bit uses the 72pin interface. After the memory development entered the SDRAM era, SIMM was gradually replaced by DIMM technology.

2.DIMM

184-pin DIMM slot

DIMM is quite similar to SIMM, except that the two ends of the golden finger of the DIMM are not interconnected like SIMM, and they transmit signals independently, so they can meet the transmission needs of more data signals. The same DIMM is used, the interface of SDRAM and DDR memory are slightly different, SDRAM DIMM is 168Pin DIMM structure, each side of the gold finger is 84Pin, gold finger has two calipers, to avoid the insertion slot, the error of the memory into the reverse and lead to burn; The DDR DIMM uses 184Pin DIMM structure, with 92Pin on each side of the gold finger and only one bayonet on the gold finger. The difference in the number of bayonets is the most obvious difference between the two. DDR2 DIMMs are 240pin DIMMs with 120pins on each side of the gold finger. Like DDR DIMMs, there is only one bayonet on the gold finger. However, the position of the bayonet is slightly different from that of DDR DIMMs, so DDR DIMMs cannot be inserted into DDR2 DIMMs. Similarly, DDR2 memory cannot be inserted into DDR DIMMs, so on some motherboards with both DDR DIMMs and DDR2 DIMMs, there is no problem of inserting the memory into the wrong slot.

240-pin DDR2 DIMM slot

3.RIMM

RIMM is the interface type used by Rambus company's RDRAM memory. RIMM memory is similar in size to DIMM, and the gold finger is also double-sided. The RIMM has a 184-pin Pin with two bayonets close together in the middle of the gold finger. The non-ECC version of RIMM has 16 bits of data width, while the ECC version is both 18 bits wide. Due to the high price of RDRAM memory, such memory is rarely seen in the DIY market, and RIMM interfaces are rare.

Two, memory module

Memory modules can be understood here simply as the number of standard memory slots that a chipset can support. Because each chipset has different levels of data depth and data width support for the memory chip, it actually determines the maximum capacity of each memory BANK, which in turn determines the number of memory banks that the chipset can support. The number of memory banks determines the number of standard memory slots, and in general, each memory slot supports two memory banks. For example, the 865PE chipset supports four dual BANK memory slots, while the 815EP chipset supports two dual BANK memory slots or three single BANK memory slots.

In the actual motherboard product, the actual number of memory slots and the standard number of chipset memory slots may be different, for example, if the 865PE motherboard is reduced from 4 to 2, this will cause the maximum memory capacity that the motherboard can support to be reduced from 4GB to 2GB; If the 865PE motherboard is increased from 4 to 6 or more, it will not increase the maximum memory capacity, still only 4GB, because the increased memory slot is actually shared with the original memory slot memory BANK, on such a motherboard will be the type of memory and capacity to make strict restrictions, in the memory module must refer to the motherboard manual.