The table below summarises the three common form factors of memory modules used in tech gadgets today: Capacity shouldn’t be an issue with modern hardware. It’s possible to get 32GB SODIMMs with DDR4 or DDR5 memory, which are not even costly. That allows for up to 64GB of RAM in a laptop with the standard two SODIMM slots, which should be more than enough for almost any task. Thermal Issues According to JEDEC [5] the maximum recommended voltage is 1.9 volts and should be considered the absolute maximum when memory stability is an issue (such as in servers or other mission critical devices). In addition, JEDEC states that memory modules must withstand up to 2.3 volts before incurring permanent damage (although they may not actually function correctly at that level). A SO-DIMM (pronounced "so-dimm" / ˈ s oʊ d ɪ m/, also spelled " SODIMM") or small outline DIMM, is a smaller alternative to a DIMM, being roughly half the physical size of a regular DIMM. The first SODIMMs had 72 pins and were introduced by JEDEC in 1997. [7] [8] [9] Before its introduction, most laptops would use propietary RAM modules which were expensive and hard to find. [7] [10] Most desktop computers use full-sized memory modules known asDIMMs. However, laptop computers and some small-footprint mini-ITX motherboards and systems use reduced-size memory modules known as small outline DIMMs (SO-DIMMs or SODIMMS).

JEDEC decided that the terms "dual-sided", "double-sided", or "dual-banked" were not correct when applied to registered DIMMs (RDIMMs). 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 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. This all makes it harder to cool the RAM. This hasn’t been a massive issue in the p. Still, thermal management will get more complex as RAM speeds increase and the power management moves onto the SODIMM with DDR5. This will likely mean SODIMMs working on the lower end of the JEDEC standardized speeds. However, most use cases will see only a minimal difference with RAM speed changes.

MicroDIMMs started out with 144 pins and now have 214 pins on the same form factor module. DIMM VS. SODIMM VS. MicroDIMM: A Comparison DIMM, SODIMM, MicroDIMM DDR2 Size Comparison

The above example applies to ECC memory that stores 72 bits instead of the more common 64. There would also be one extra chip per group of eight, which is not counted.DIMMs started out with a 100-pin configuration – the copper connectors you see toward the bottom of the modules. However, due to the advancements in technology and the different DDR types, the DIMM modules now have 288 pins in a DDR5. SODIMM 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. a b c d e f g https://www.google.com/books/edition/Upgrading_and_Repairing_Laptops/xCXVGneKwScC?hl=en&gbpv=0

a b https://www.google.com/books/edition/Upgrading_and_Repairing_PCs/E1p2FDL7P5QC?hl=en&gbpv=1&dq=simm+32+bits+dimm+64+bits&pg=PA442&printsec=frontcover Higher-speed DDR2 DIMMs can be mixed with lower-speed DDR2 DIMMs, although the memory controller will operate all DIMMs at same speed as the lowest-speed DIMM present. JEDEC standard: DDR2 SDRAM Specification: JESD79-2F, November 2009 ** http://www.jedec.org/standards-documents/docs/jesd-79-2e SO-DIMM [ edit ] A 200-pin PC2-5300 DDR2 SO-DIMM A 204-pin PC3-10600 DDR3 SO-DIMM A SO-DIMM slot on a computer motherboardDouble data rate 2 SDRAM (DDR2 SDRAM) is the successor to DDR SDRAM. DDR2 SDRAM runs its external data bus at twice the speed of DDR SDRAM and features a four-bit prefetch buffer, enabling faster performance. However, DDR2 SDRAM memory has greater latency than DDR SDRAM memory. Latency is a measure of how long it takes to receive information from memory; the higher the number, the greater the latency. Typical latency values for mainstream DDR2 memory are CL=5 and CL=6, compared to CL=2.5 and CL=3 for DDR memory. 240-pin memory modules use DDR2 SDRAM. Ever-increasing amounts of RAM are needed as operating systems and applications get more powerful and add more features. Because RAM is one of the most popular upgrades to add to any laptop or desktop system during its lifespan, you need to understand how RAM works, which types of RAM exist, and how to add it to provide the biggest performance boost to the systems you maintain.

If you have been in the tech industry for a while, you will know that there are different types and sizes of RAM/memory modules available. When referring to RAM sizes, we mean its physical size, and not its capacity (4 GB, 16 GB, etc.). Samsung Electronics Announces JEDEC-Compliant 256Mb GDDR2 for 3D Graphics". Samsung Electronics. Samsung. 23 August 2003 . Retrieved 26 June 2019.pin, with different notch position than on DDR4 SO-DIMMs, used for UniDIMMs that can carry either DDR3 or DDR4 SDRAM