Checkout the performance results of NCache in distributed environments. These tests were conducted in an Amazon AWS environment.
In our latest benchmarks, we have successfully demonstrated that NCache can linearly scale and achieve 2 Million transactions per second with only a 5-server cache cluster. NCache delivers this performance with sub-microsecond latency. The scalability is linear which means that if you add more cache servers, NCache will deliver higher transaction throughput.
You can reach the Benchmark Whitepaper or watch the actual benchmarking video so you can see how these benchmarks were done.
A Detailed document, explaining the benchmarks
Demonstration video showing actual benchmarks being done