Crucial CT25664AC800 2 GB DDR2 800 MHz (PC2-6400) CL6 SODIMM 200-Pin Memory

Product Information

Designed for use with Intel Skylake (6th generation Core i-series CPU); memory controller on motherboard/ processor must support both DDR3 and DDR4 memory

RAM Types—This section provides the information you need to understand memory chip and module types and how some types of memory are designed to correct memory errors. SO-DIMM vs DIMM—In this section, you learn the differences between memory modules made for desktop and those made for laptop computers. DIMMs are often referred to as "single-sided" or " double-sided" to describe whether the DRAM chips are located on one or both sides of the module's printed circuit board (PCB). However, these terms may cause confusion, as the physical layout of the chips does not necessarily relate to how they are logically organized or accessed. There’s DDR4, DDR5, and their predecessors. These are the types of memory modules that define how the particular type of module will perform in terms of throughput, power consumption, latency, etc. DDR2 SDRAM was first produced by Samsung in 2001. In 2003, the JEDEC standards organization presented Samsung with its Technical Recognition Award for the company's efforts in developing and standardizing DDR2. [1]

Use a digital camera or smartphone set for close-up focusing so you can document the system’s interior before you start the upgrade process.

RAM is used for programs and data as well as by the operating system for disk caching (using RAM to hold recently accessed information). Thus, installing more RAM improves transfers between the CPU and both RAM and hard drives. If your computer runs short of RAM, the operating system can also use the hard drive as virtual memory, a slow substitute for RAM. Although the hard drive can substitute for RAM in a pinch, don’t confuse RAM with mass storage devices such as hard disks or SSDs. Although the contents of RAM and mass storage can be changed freely, RAM loses its contents as soon as you shut down the computer, while magnetic storage can hold data for years. Although RAM’s contents are temporary, RAM is much faster than magnetic or SSD storage; RAM speed is measured in nanoseconds (billionths of a second), while magnetic and SSD storage is measured in milliseconds (thousandths of a second).Buffered (registered) memory modules can be built with or without ECC support. However, most buffered memory modules are used by servers and include ECC support. Figure 4-2 compares a standard (unbuffered) memory module with a buffered (registered) memory module that also supports ECC. SO-DIMM vs DIMM

When you install memory on a motherboard inside a working system, use the following tips to help your upgrade go smoothly and the module to work properly: Variety of Capacities and Speeds: SODIMMs are available in a range of capacities and speeds, allowing users to choose the memory configuration that best meets their needs. https://www.google.com/books/edition/Peter_Norton_s_New_Inside_the_PC/O0FTac_k7CIC?hl=en&gbpv=1&dq=laptop+proprietary+sodimm&pg=PA36&printsec=frontcover User Upgradeable: Many laptops and SFF machines have user-accessible memory slots, making it relatively straightforward to upgrade the memory by replacing or adding SODIMMs.Most types of desktop memory modules use unbuffered memory. However, many servers and some desktop or workstation computers use a type of memory module called registered memory or buffered memory: buffered memory is the term used by the 220-901 exam. Buffered (registered) memory modules contain a register chip that enables the system to remain stable with large amounts of memory installed. The register chip acts as a buffer, which slightly slows down memory access. For use in computers, DDR2 SDRAM is supplied in DIMMs with 240 pins and a single locating notch. Laptop DDR2 SO-DIMMs have 200 pins and often come identified by an additional S in their designation. DIMMs are identified by their peak transfer capacity (often called bandwidth). Memory Upgrade Considerations—This section lists the many different factors you need to take into account when selecting RAM for a particular system. For critical applications, network servers have long used a special type of memory called error-correcting code (ECC). This memory enables the system to correct single-bit errors and notify you of larger errors.