MemTest86 vs y-cruncher

MemTest86 is a bootable utility that checks computer RAM for faults using memory test algorithms and patterns. It runs from a USB drive without an installed operating system, although Windows, Linux, or an Intel-based Mac can be used to create that drive. Version 11.7 requires UEFI firmware and x86 or ARM64 hardware, and does not support Apple Silicon M-series Macs. Its listed coverage includes 14 algorithms, such as SIMD, Row Hammer, and DMA tests, and support for DDR2, DDR3, LPDDR4, LPDDR5(x), ECC, CDIMM, and CAMM2 memory. It can create customizable HTML reports and, on supported configurations, decode an error address to identify a failed DIMM or chip. The Free Edition supports up to 16 CPU cores; Pro supports up to 512 and adds automation and custom tests. Site Edition adds PXE-based LAN deployment and Management Console integration. The Free Edition costs nothing; Pro Download costs $116, paid once.

y-cruncher calculates Pi and other mathematical constants to trillions of digits, and also serves as a multithreaded benchmark and stress-testing program for overclockers and hardware enthusiasts. For most constants, it uses separate algorithms to compute and verify results. Its multithreading uses modern multi-core processors without significantly increasing memory usage, and it supports SIMD instruction sets such as SSE, AVX and AVX512. For computations that exceed available memory, y-cruncher manages swap space and can use multiple drives for disk swapping. It can detect and correct minor errors attributed to hardware instability or software bugs. Windows and Linux downloads are available; the listed requirements are Windows 8 or later, 64-bit Linux, and an x86 or x64 processor. The Linux static build lacks TBB and NUMA binding, while the dynamic build supports all features but is less portable. The free plan permits non-commercial and academic use; commercial-purpose licensing may be available by contacting the developer. Major algorithm redesigns and rewrites are on hiatus, though maintenance and some processor optimizations continue.