Their blog post goes into detail on how they are benchmarking and they use the benchmarking tool developed by Redis [1]
> We ran our tests on AWS Graviton2 EC2 instances, which are network-optimized and provide the best performance for web applications. We used memtier_benchmark — a widely used benchmarking tool developed by Redis Ltd. — to test throughput and latency, and Prometheus to monitor and visualize memory usage.
It is easy to reproduce and check the claims. Redis also countered with a blog post [2]