Are there different types of RAM?
Yes, there are multiple types of RAM. As with other forms of computer hardware, scientists are always trying to decrease energy consumption while increasing speed and capacity. RAM has been around since the first days of computing, and in early microcomputing eras it required enthusiasts to plug in chips one at a time. Things have come a long way since then.
By the late 1990s and early 2000s, the main types of RAM were SRAM (static RAM), DRAM (Dynamic RAM), and SDRAM (Synchronous Dynamic RAM).
Today, the most common type of RAM is DDR-SDRAM, or Double Data Rate Synchronous Dynamic Random-Access Memory. And there are various iterations, including DDR2, DDR3, DDR4, and even DDR5.
DDR (double-data rate) allows simultaneous multiple file transfers. The latest version of DDR5-RAM can achieve data rates of about 6.4 gigabytes per second. But supply-chain shortages make DDR5 difficult to get — and very expensive.
The most commonly used RAM is still DDR4 memory, which also comes in multiple types and speeds. Generally, these memory sticks run at or above speeds of 2,400MHz. If you want to squeeze maximum performance out of your memory, you can get higher clocked RAM ranging from 3,200MHz all the way up to 5,000MHz (which is important for gamers and GPU overclockers). The more MHz your RAM has, the faster it runs.
There’s also VRAM (Video Random Access Memory), which is used in graphics cards to process graphical data during gaming, photo editing, or other graphics-heavy activities. Video RAM is even faster than normal memory, and it usually comes in the form of GDDR (Graphics Double Data Rate), which is a specific type of memory optimized for graphics rendering. The latest generation — GDDR6 — can achieve a data rate of 16 Gbps.
Some top-end graphics cards use another type of VRAM known as High Bandwidth Memory — but this type of RAM is hard to find and certainly not cheap.
DRAM vs SRAM
SRAM (static RAM) and DRAM (dynamic RAM) are common types of RAM that each use different technology to store data. Whereas SRAM uses transistors that preserve memory as long as they receive a steady trickle of power, DRAM uses capacitors that need to be periodically “refreshed” by comparatively large bursts of energy every few milliseconds.
The main difference between SRAM vs DRAM based on dynamic capacitors is that while SRAM technology is smaller, faster, and more energy efficient, it’s also much more expensive. For this reason, SRAM is typically used for cache memory, while DRAM is usually used in a computer’s main memory.
Most modern computers now use an upgraded form of DRAM known as synchronous DRAM, or SDRAM. Although SDRAM is much faster than legacy DRAM, it’s still slower than SRAM and consumes a lot of power.
What is ROM?
ROM, or read-only memory, is a form of memory that a computer can read but not write onto. ROM is often used to store and play back music (CDs) or movies (DVDs). Unlike RAM, a computer can’t write new data onto ROM, it can only read it, or play it back.