fio vs OCCT

fio is a free storage I/O workload simulator for performance testing and reproducing bugs. Its job files can define multiple threads, processes and files, with sequential, random or mixed reads and writes using buffered, direct or raw I/O. Tune block and I/O size, I/O engine, queue depth, target files or devices, and job count. Documented engines include Linux io_uring and libaio, POSIX asynchronous I/O, and synchronous read/write options. Separate engines support HTTP GET and PUT requests to WebDAV or S3 endpoints and access to Ceph RADOS and RBD. Verification options can check written data after a workload, including repeated burn-in tests. Results are available in normal text, terse, JSON and JSON+ formats, plus bandwidth and latency logs; terse output is intended for scripts, tables or graphs. fio supports Linux, Solaris, AIX, HP-UX, macOS, NetBSD, OpenBSD, Windows, FreeBSD and DragonFly. The HTTP engine supports direct I/O only at depth 1, with scaling through multiple jobs.

OCCT is a PC tool for stability and stress testing, benchmarking, and system monitoring. Its tests cover CPU, GPU, memory, VRAM, and power supplies, while CPU and memory benchmarks include memory latency and bandwidth measurements. System monitoring and system information use HwInfo. OCCT runs on Windows and Linux. The free Personal edition is for individual use, including PC enthusiasts, overclockers, and gamers, and cannot be used in a commercial or business environment. Personal users need one license per household. Supporter costs €4.50 per month and adds unlimited test duration, no wait time, test reports, and stability certificates; Supporter+ costs €7.00 per month and adds more certificate slots. Pro, Enterprise, and Enterprise+ are the editions directed to business users, with prices available on request, and professional licenses are specific to Windows or Linux. Enterprise includes JSON, CSV, and PDF report export and command-line test automation. It can also run portably from a USB drive or network location without installation or internet access; the On-Premise option keeps system and test data within the customer's infrastructure.