UFS 2.2 is the definitive winner in performance. There is no metric where eMMC 5.1 beats UFS 2.2, except cost.
You won't notice the difference when looking at a static photo. You will notice it during transitions. ufs 22 vs emmc 51 link
Sequential Write:
Random Read/Write (IOPS):
UFS 2.2 supports full-duplex (read + write simultaneously). eMMC is half-duplex (must finish one before starting the other). This means app launches, multitasking, and gallery loading are noticeably smoother on UFS. Sequential Write:
While real-world performance depends on the controller and NAND type, the theoretical specifications paint a clear picture. Random Read/Write (IOPS): UFS 2
| Feature | eMMC 5.1 | UFS 2.2 | | :--- | :--- | :--- | | Interface | Parallel (Half-Duplex) | Serial (Full-Duplex) | | Max Theoretical Speed | ~400 MB/s | ~1,200 MB/s | | Sequential Read | 250–300 MB/s | 800–1,000 MB/s | | Sequential Write | 150–200 MB/s | 250–500 MB/s | | Random Read (IOPS) | 10k–20k | 50k–100k | | Command Queuing | Limited (1 queue) | Deep (32 queues) |
eMMC (embedded MultiMediaCard) is a legacy storage standard that has been around for over a decade. Think of it as the SD card you put in a camera, but soldered directly onto the phone’s motherboard.