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Prime95 vs Karhu RAM Test: catalog facts
Prime95	Karhu RAM Test
Free Free to download and use under the GIMPS free software license.	Paid Sold as a paid license by Karhu Software.
Windows, macOS, Linux	Windows
Standard, demanding CPU and memory stress test Builds for Windows, macOS, Linux and FreeBSD	Runs inside Windows without rebooting Built for validating memory overclocks
Not an OSI open source license Dated interface	Windows only; Linux support was announced but not shown as available Paid license
Downloadable app	Downloadable app
Closed source	Closed source
License: GIMPS free software license	License not stated
Not stated if an account is needed	Not stated if an account is needed
Works offline	Works offline
Official website Full listing and sources Checked October 1, 2026	Official website Full listing and sources Checked October 2, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.