Garnet

Your existing Redis clients work with it out of the box.

Free and open source under MIT. Garnet's key selling points: it uses Microsoft's FASTER storage engine under the hood, which is designed for modern SSDs and multi-core CPUs. Benchmarks show significantly higher throughput than Redis for both reads and writes, especially on machines with NVMe drives and many cores. It supports the most common Redis commands, Lua scripting, pub/sub, and cluster mode.

No paid tier exists. Microsoft released this as a research-backed open source project. Solo/small teams: stick with Redis unless you have a specific performance bottleneck. Growing teams on .NET stacks: natural fit. Anyone with NVMe hardware and high-throughput requirements: worth benchmarking against Redis and KeyDB.

The catch: it's new. Released in early 2024, the Redis command coverage isn't 100%. Some less common commands and modules aren't supported yet. The community is small compared to Redis's massive ecosystem. If your application uses Redis Streams, RedisJSON, or RediSearch modules, Garnet doesn't support those. And running a .NET runtime for your cache layer might feel odd if your stack is otherwise non-.NET.