AWS Compute Blog

Amazon ElastiCache performance boost with Amazon EC2 M5 and R5 instances

Contributed by Ruchita Arora, Sr. Product Manager, Allen Farris, Software Dev Engineer, and Itay Maoz, Sr. Software Engineering Manager

Earlier this year, Amazon EC2 introduced two exciting new instance families, M5 and R5. These instances are based on the new AWS Nitro system, a combination of dedicated hardware and lightweight hypervisor that aims to deliver performance indistinguishable from bare-metal performance. These new instance families deliver up to 25 Gbps of aggregate network bandwidth, with enhanced networking based on the Elastic Network Adapter (ENA).

R5 and M5 instances feature custom hardware and custom Intel Xeon Scalable processors to enable a sustained all core frequency of up to 3.1 GHz and support Intel Advanced Vector Extension 512 (AVX-512). The latest fifth generation EC2 instances offer up to 50% more vCPUs and 60% more memory over the previous generation instances, and larger r5.24xlarge and m5.24xlarge instances.

Amazon ElastiCache

Amazon ElastiCache offers a Redis or Memcached-compatible, fully managed, in-memory data store and caching service in the cloud. The service embodies much of what makes fast data a reality for customers who are looking to process a high volume of data at incredible rates, faster than traditional databases.

As part of adding support for M5 and R5 instances in ElastiCache, we spent the time to take advantage of the AWS Nitro-based system and optimize these instances for ElastiCache for Redis. Developers love the performance, simplicity, and in-memory capabilities of Redis, making it among the most popular NoSQL key-value stores. Redis’s microsecond latency has made it a default choice for caching. The support for advanced data structures (for example, lists, sets, and sorted sets) also enables a variety of in-memory use cases such as leaderboards, in-memory analytics, messaging, and more.

Optimizing performance for ElastiCache for Redis

We started with the M5 and R5 instances and tuned performance by optimizing the Amazon Linux operating system configuration on these instances to maximize network performance for running in-memory workloads.

Using the open-source benchmarking tool rpc-perf, we ran a Redis benchmark with 14.7 million unique keys, 200-byte string values, 80% gets, 20% sets, and no command pipelining. We ran this benchmark on 20 client instances connecting to an optimized R5 instance in the same Availability Zone. We saw up to 30% more transactions per second than running ElastiCache for Redis on the same size instance with the default Linux configuration. For details, see the following table.

Vanilla R4 Vanilla R5 Tuned R5 Vanilla R4 to Tuned R5 Improvement
large 88,000 RPS 179,000 RPS 215,000 RPS 144%
xlarge 93,000 RPS 180,000 RPS 207,000 RPS 122%
2xlarge 107,000 RPS 187,000 RPS 217,000 RPS 102%
4xlarge 131,000 RPS 208,000 RPS 225,000 RPS 71%
8xlarge/12xlarge 128,000 RPS 211,000 RPS 247,000 RPS 92%
16xlarge/24xlarge 149,000 RPS 181,000 RPS 237,000 RPS 59%

We also reduced average (p50) and tail (p99) latencies up to 23%, resulting in average latencies as low as 350 microseconds after these optimizations. The optimized M5 instances yielded 9%-42% incremental requests per second and better CPU utilization for ElastiCache for Redis workloads.

For the same caching use case scenario, ElastiCache for Redis optimized R5 instances benefited from a significant performance improvement over self-managed Redis on R4 instances. The optimized R5 instances supported 59%-144% more transactions per second than similarly sized R4 instances.

We saw similar incremental performance improvements on optimized M5 instances relative to previous generation M4 instances. The optimized M5 instances benefited from throughput improvements of up to 356% relative to previous generation M4 instances.

Among the M5 instances, the most significant improvements were in the smaller size of the M5 family. They take advantage of ENA performance with burst networking up to 10 Gbps for the m5.large through m5.4xlarge sizes, which is useful for handling infrequent traffic spikes.


We are excited to bring these new instances to customers. You benefit from less hypervisor overhead and better networking, but you also see a dramatic upside from the performance tuning work that the ElastiCache team did to take advantage of the AWS Nitro system. This is just the beginning.

Our performance team is continuing to enhance the full system for optimal ElastiCache for Redis performance, which we are rolling out in the coming months. To get started with ElastiCache on the new M5 and R5 EC2 instances, see the AWS Management Console.