By Physical Form Factor
- 2.5-inch SATA SSD: The most common type for older laptops and desktops. It looks like a thin smartphone and uses the same cables as a traditional hard drive, making it a “drop-in” replacement for slower mechanical drives.
- M.2 SSD: A small, rectangular drive about the size of a stick of gum. These plug directly into a slot on the motherboard, eliminating the need for cables.
- mSATA (Mini-SATA): A smaller version of the standard SATA SSD, used mostly in older ultrabooks and compact devices before M.2 became the standard.
- Add-in Card (AIC): These look like graphics cards and plug into a PCIe slot. They are typically used for extreme performance in workstations or servers where high heat dissipation is needed.
By Connection Interface (Protocol)
- SATA: The older and slower standard. It is capped at around 550–600 MB/s. It is affordable and perfect for general office work or revitalizing an old PC.
- NVMe (via PCIe): The modern standard for speed. By connecting directly to the CPU, NVMe drives can reach speeds from 3,500 MB/s (Gen 3) up to 14,000+ MB/s (Gen 5).
By Internal NAND Technology
The type of flash memory used inside the drive affects its lifespan and price:
- TLC (Triple-Level Cell): The current “sweet spot” for most users, balancing good performance and longevity at a fair price.
- QLC (Quad-Level Cell): The cheapest option, offering huge storage capacities (e.g., 4TB or 8TB) but with slower write speeds and lower durability.