Overview

MemTest86 is a USB-bootable RAM diagnostic for people tracking down memory faults or checking whether RAM is behind system instability. It is most useful to system builders, repair shops, overclockers, and PC manufacturers. Its focused testing and standalone operation are strengths, but strict hardware requirements rule out some machines.

Key features

MemTest86 runs memory test patterns outside the installed operating system, which makes it useful when instability makes normal troubleshooting difficult. Its 14 listed algorithms include SIMD, Row Hammer, and DMA tests, and it supports DDR2, DDR3, LPDDR4, LPDDR5(x), ECC, CDIMM, and CAMM2 memory. This is substantial coverage for RAM diagnosis, but it is not a general-purpose hardware maintenance suite.

Customizable HTML reports preserve results, and on supported configurations error-address decoding can point to a failed DIMM or chip. That extra specificity can help turn a memory error into a more actionable repair lead, though component identification depends on the configuration. Pro adds full test automation and custom tests configured through a file; Site Edition adds PXE-based LAN deployment and PassMark Management Console integration and reporting, features most relevant to organizations managing many machines.

The binaries support Secure Boot and are signed by Microsoft to verify code integrity. The program itself is operating-system independent, though a Windows, Linux, or Intel-based Mac computer can be used to create its bootable USB drive.

Pricing

The Free Edition costs 0.00 USD per free and has no usage restrictions, but it supports up to 16 CPU cores and receives support through the public forum. That is a sensible starting point for individual diagnostics within the core cap.

Pro Download costs 116.00 USD per once, billed $116.00. It supports up to 512 CPU cores and adds full automation and configuration-file custom tests. Pro USB Flash Drive costs 144.00 USD per once, billed $144.00 plus shipping, and suits buyers who want the boot media supplied rather than creating it themselves. Both Pro options license one machine running Pro at the same time, include phone, email, and forum support, and provide 12 months of free upgrades.

Site Edition costs 5557.00 USD per once, billed $5557.00. It adds scalable PXE LAN deployment and Management Console integration and reporting, with unlimited users within one organization in one country. Its price and organizational scope make it a specialist choice for larger deployment workflows, not a natural upgrade for occasional single-machine checks. No paid edition is described as a subscription; the listed license and upgrade terms are the relevant limits.

Platforms

MemTest86 supports Linux, macOS, self-hosted, and Windows environments, but version 11.7 requires UEFI firmware and x86 or ARM64 hardware. It does not support Apple Silicon M-series Macs. Because the diagnostic boots independently of an OS, check the machine's firmware and processor architecture before choosing it; Mac support does not extend to every Mac.

Who it's for

Choose MemTest86 when a builder, repair technician, overclocker, or PC maker needs a dedicated way to diagnose RAM faults or rule memory out as the cause of instability. Free Edition is appropriate for work within its 16-core ceiling; Pro makes more sense when the 512-core support, automation, or custom tests matter. Site Edition is aimed at organizations that need LAN-scale deployment. Look elsewhere if you need a wider range of hardware diagnostics or use an unsupported Apple Silicon Mac.

Pros and cons

Pros: Standalone booting keeps RAM checks independent of the installed OS, useful when troubleshooting an unstable computer.
Pros: Fourteen algorithms and broad listed memory support give it range across memory diagnostic tasks.
Pros: HTML reporting and supported error-address decoding can help preserve findings and identify a likely failed component.
Pros: Pro and Site add meaningful options for automated testing and multi-machine deployment.
Cons: UEFI and x86 or ARM64 requirements, plus the lack of Apple Silicon support, narrow compatibility.
Cons: Free Edition's 16-core cap may be insufficient for some systems; raising it requires a paid Pro license.
Cons: Pro is licensed per machine running it at the same time, while Site's one-country organizational scope limits its fit for broader deployments.

Alternatives

For another standalone memory tester, MemTest86+ is free and open source under GPLv2, including for private or commercial use. Pick it if that licensing matters more than MemTest86's listed Pro automation and Site deployment options.

smartmontools is a free option for Linux, macOS, and Windows built around the smartctl and smartd utilities; choose it for that utility-based alternative rather than MemTest86's RAM-focused testing.

stress-ng is a free, always-free tool spanning Android, Linux, macOS, self-hosted, and Windows. Consider it when that broader platform range or free availability is the priority.

Hard Disk Sentinel is another option with a free Linux version and a limited free trial; its listing also includes a DOS plan.

PC-Doctor Toolbox offers a free personal-use plan for up to five personal systems, requiring a Toolbox Remote account and opting in to technical and interaction data sharing; choose it if those personal-use terms suit your needs.

Blackwire Drive Eraser & Sanitizer is a Windows drive-erasure option, with its free tier limited to personal or noncommercial use and two drives at once; choose it for drive sanitization rather than RAM diagnosis.

Intel VTune Profiler is a free download for Linux, self-hosted, and Windows, available standalone or through Intel oneAPI Toolkit; it is a different choice for readers seeking that profiling tool.

Ultimate Boot CD is a free downloadable ISO image; choose it if you want that bootable disc option instead.

Browse Hardware Diagnostic Software for related tools, or PC Overclocking Software if your priority is overclocking software.

Verdict

MemTest86 is a strong fit for PC builders and repair professionals who need a dedicated, OS-independent RAM diagnostic, with paid upgrades for higher core support and deployment automation. Its test coverage and reporting make it more capable than a basic fault check, but the UEFI and architecture requirements are decisive: verify compatibility first, and choose another tool if you need broader diagnostics or Apple Silicon support.

	MemTest86	Prime95
Free plan	Yes	Yes
Free trial	No	No
Paid from	Free	Free
Open source	No	No
Platforms	Linux, macOS, self-hosted, Windows	Linux, macOS, self-hosted, Windows
Free plan	Yes	Yes

MemTest86 vs Prime95

MemTest86

Prime95