The study analyzed the performance of different Linux system calls on various storage devices, including HDD, SATA SSD, NVMe SSD, and Intel Optane. The researchers found that solid-state devices (SSDs) outperformed hard disk drives (HDDs) in terms of read latency, with Intel Optane offering the lowest latency among all four options. However, Intel Optane had its own drawback compared to NVMe SSD, which was only two times faster than HDD for large block sizes. The optimal block size for random reads varied across devices, ranging from 256 kilobytes for HDD to 8 kilobytes for Intel Optane. The study highlighted the importance of considering device-specific characteristics when optimizing I/O performance in Linux.