SDS (symmetric double sided)

SDS, or Symmetric Double Sided, refers to a type of memory module or DIMM (Dual In-Line Memory Module) configuration commonly used in computer systems. It is a design that allows for memory chips to be placed on both sides of the module, effectively doubling the memory capacity without increasing the physical size of the module.

Here's a detailed explanation of SDS:

1. Memory Modules: In computer systems, memory modules are used to store and access data. DIMMs are the most common type of memory modules found in desktop and server systems. They consist of a small circuit board with memory chips attached to it.
2. Single-Sided vs. Double-Sided DIMMs: Memory chips are typically mounted on only one side of a DIMM module, referred to as single-sided DIMMs. This allows for a certain amount of memory capacity based on the number of chips that can fit on that side. For example, a single-sided DIMM might have eight memory chips, each with a capacity of 1 GB, resulting in a total memory capacity of 8 GB.
3. SDS Design: In an SDS configuration, memory chips are mounted on both sides of the DIMM module, effectively utilizing both sides of the circuit board. This allows for double the number of memory chips to be installed on the module, thereby doubling the memory capacity without increasing the physical size.
4. Memory Chip Organization: Each memory chip on the SDS DIMM has a certain capacity, usually measured in gigabits (Gb) or gigabytes (GB). The total capacity of the DIMM is determined by the number of chips and their individual capacities. For example, if each chip has a capacity of 2 Gb, and there are eight chips on each side of the SDS DIMM, the total memory capacity would be 2 Gb/chip * 8 chips/side * 2 sides = 32 GB.
5. Addressing and Data Lines: SDS DIMMs require additional addressing and data lines to support the increased number of memory chips. The memory controller in the computer system must be able to access and manage the memory cells on both sides of the module. This is typically achieved through the use of additional circuitry on the DIMM module.
6. Compatibility: SDS DIMMs are designed to be compatible with systems that support this memory configuration. However, it's essential to check the motherboard or system specifications to ensure compatibility. Some systems may have restrictions on the maximum memory capacity or specific requirements for memory module configurations.
7. Performance Considerations: SDS DIMMs can provide increased memory capacity, allowing for more data to be stored and accessed simultaneously. This can be beneficial for applications that require large amounts of memory, such as virtualization, database management systems, or scientific simulations. However, it's important to note that memory performance is not solely determined by capacity but also by factors like memory speed, latency, and memory controller capabilities.

In summary, SDS (Symmetric Double Sided) refers to a memory module configuration where memory chips are mounted on both sides of the DIMM, effectively doubling the memory capacity without increasing the module's physical size. It allows for increased memory capacity in systems that support this configuration, but compatibility and performance considerations should be taken into account when using SDS DIMMs.