How do read/write speeds vary between persistent storage types?

Read/write speeds can significantly vary between different types of persistent storage, such as HDDs, SSDs, and NVMe SSDs.

Hard Disk Drives (HDDs) are the oldest type of persistent storage and have the slowest read/write speeds. This is because they use mechanical parts, such as a spinning disk and a moving read/write head. The speed of an HDD is determined by its revolutions per minute (RPM), with higher RPMs leading to faster speeds. However, even the fastest HDDs can't match the speeds of Solid State Drives (SSDs) or NVMe SSDs.

Solid State Drives (SSDs) are much faster than HDDs because they use flash memory to store data, which allows for quicker data access and transfer. Unlike HDDs, SSDs have no moving parts, so they can read and write data almost instantly. The read/write speeds of SSDs can vary depending on the type of flash memory they use. For example, SSDs that use NAND flash memory are slower than those that use SLC or MLC flash memory.

NVMe SSDs are the fastest type of persistent storage currently available. NVMe stands for Non-Volatile Memory Express, and it's a protocol designed to make the most of SSDs' speed. NVMe SSDs connect directly to the computer's motherboard via the PCIe (Peripheral Component Interconnect Express) interface, which allows for faster data transfer than the SATA interface used by regular SSDs and HDDs. As a result, NVMe SSDs can achieve read/write speeds that are several times faster than those of regular SSDs and HDDs.

In conclusion, the read/write speeds of persistent storage types can vary greatly, with NVMe SSDs being the fastest, followed by regular SSDs, and then HDDs. However, it's important to note that faster read/write speeds often come with a higher price tag, so you'll need to consider your budget as well as your speed requirements when choosing a type of persistent storage.