The correct answer is Dynamic Random Access Memory (DRAM). It must be refreshed many times per second to store information, otherwise, it will lose what it is holding. Hence, Option 2 is correct. It is the most common type of memory in use today.
Dynamic random access memory (DRAM) circuits require periodic refresh operations to prevent data loss. As DRAM density increases, DRAM refresh overhead is even worse due to the increase of the refresh cycle time.
A DRAM storage cell is dynamic, meaning that it needs to be refreshed or given a new electronic charge every few milliseconds to compensate for charge leaks from the capacitor.
Static Random Access Memory (SRAM) also needs constant power to hold on to data, but it doesn't need to be continually refreshed the way DRAM does.
Dynamic RAM (DRAM)
In dynamic RAM, electricity always has to be moving through the chip to keep refreshing the memory. DRAM is the basic type of memory chip, and everything that came later was mainly a way to get address information faster.
Although all RAM basically serves the same purpose, there are a few different types commonly in use today: Static RAM (SRAM) Dynamic RAM (DRAM) Synchronous Dynamic RAM (SDRAM)
Static Random Access Memory (SRAM)
Data is stored in transistors and requires a constant power flow. Because of the continuous power, SRAM doesn't need to be refreshed to remember the data being stored. SRAM is called static as no change or action i.e. refreshing is not needed to keep the data intact.
SRAM has a lower access time and is faster, whereas DRAM has a higher access time and is slower compared to SRAM. SRAM uses transistors and latches, while DRAM uses capacitors and very few transistors.
SRAM stores information with the help of transistors. DRAM stores data using capacitors. In SRAM, capacitors are not used which means refresh is not needed. In DRAM, contents of a capacitor need to be refreshed periodically.
For exam- ple, all DDR3 devices require refresh rate of 7.8 us at normal temperature range (0–85 C), and 3.9 us at extended temperature range (up to 95 C).
Its static nature means it does not require refreshing.
SRAM uses flip-flops to store data. This makes SRAM faster and more efficient than DRAM, as it does not require constant data refreshing. SRAM is faster and more expensive than DRAM. It uses a small number of transistors to store each bit of data, which allows for faster access times.
Because SRAM uses flip-flops, which can be made of up to 6 transistors, SRAM needs more transistors to store 1 bit than DRAM. If we compare, DRAM only uses a single transistor and capacitor. Thus, SRAM requires a higher number of transistors for the same amount of memory. All this increases the production cost.
Unlike dynamic RAM (DRAM), which must be continuously refreshed, SRAM does not have this requirement, resulting in better performance and lower power usage. However, SRAM is also more expensive than DRAM, and it requires a lot more space.
What are the types of RAM? There are two main types of RAM: Dynamic RAM (DRAM) and Static RAM (SRAM). DRAM (pronounced DEE-RAM), is widely used as a computer's main memory. Each DRAM memory cell is made up of a transistor and a capacitor within an integrated circuit, and a data bit is stored in the capacitor.
NVRAM (non-volatile random-access memory) refers to computer memory that can hold data even when power to the memory chips has been turned off.
All RAM types, including DRAM, are a volatile memory that stores bits of data in transistors.
SRAM is either present on the processor or it is fixed between the processor and the main memory of a device. DRAM is present on the motherboard of a device. SRAM is faster than DRAM since it has a faster access time. DRAM is slower than SRAM.
A DRAM cell is composed of an access transistor and a capacitor. Data is stored in the capacitor as electrical charge, but electrical charge leaks over time. Therefore, DRAM must be refreshed periodically to preserve the stored data. Refresh negatively impacts DRAM performance and power dissipation.
The JEDEC standard for current memory standards requires all rows in a DRAM chip to be refreshed every 64ms. To prevent performance loss, the process is performed opportunistically every 64ms refreshing the whole DRAM chip in one batch.
In the DRAM operation of the external pin, the interface is maintained by an externally applied clock signal. For DRAM continuous refreshing clock cycles are required for the retention of data stored.
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.
What are the advantages of DDR4 over DDR3? DDR4 modules are more energy-efficient, operating only at 1.2V compared with DDR3's 1.5V or 1.35V. The reduced power consumption gives substantial power savings and allows operation at higher speeds without higher power and cooling requirements.
To sum it up: Static RAM is fast and expensive, and dynamic RAM is less expensive and slower. Therefore, static RAM is used to create the CPU's speed-sensitive cache, while dynamic RAM forms the larger system RAM space.