The differences between PCIe and SATA are as follows:
1. Different interface types:
SATA (Serial ATA) is a connection interface used by SSDs for data communication with the system. It was created in 2003, which means it has had a lot of time to solidify itself as one of the most widely used connection types today.
PCIe (Peripheral Component Interconnect Express) can be considered a more direct data connection to the motherboard. It is typically used in devices such as graphics cards, which also require extremely fast data connections.
2. Different speeds:
SATA 3.0 is the most popular form of SSD, with a theoretical transfer speed of 6 Gb/s (750 MB/s). But due to some physical deviations in how the encoding transfers data, it actually has a real-world transfer speed of 4.8 Gb/s (600 MB/s).
PCIe 3.0 has an effective transfer speed of 985 MB/s per lane, and since PCIe devices can support 1x, 4x, 8x, or 16x lanes, you can increase the potential transfer speed to 15.76 GB/s.
3. Different interface protocols:
The interfaces include AHCI protocol and NVMe protocol. AHCI is older and designed for HDD and SATA, which means PCIe SSD using AHCI may not reach its maximum potential. NVMe is designed for use with PCIe, so it performs better.