AWS r6idn.16xlargevsAWS r6idn.2xlarge

r6idn.16xlarge pairs 64 vCPUs with 512GB of RAM at $6.2525/hr On-Demand (about $4502/mo at 24×7). r6idn.2xlarge pairs 8 vCPUs with 64GB at $0.7816/hr (~$563/mo). r6idn.2xlarge is 87% cheaper per hour than r6idn.16xlarge ($5.4709/hr gap).

Because both instances are in the **r6idn family**, the only thing that changes between them is sizing — same silicon, same architecture (Intel Xeon (x86_64)), same burstable/sustained behavior. The choice is purely about how much capacity you actually need: r6idn.16xlarge gives you 64 vCPUs and 512GB of RAM, r6idn.2xlarge gives you 8 vCPUs and 64GB. AWS scales pricing close to linearly within a family, so picking the right size is mostly about right-sizing your workload, not getting a better deal per vCPU.

Benchmark data for at least one of these instances is still being collected, so a direct performance-per-dollar comparison isn't possible yet. Sysbench scores are pending for r6idn.16xlarge and 2975/12370 for r6idn.2xlarge. Check back as the benchmark queue completes — newer-generation instances typically score 10–30% higher on single-thread and 15–50% higher on multi-core vs the previous generation in the same series.

In practice, pick r6idn.16xlarge when your workload is closer to memory-optimized (memory-bound work — in-memory databases, real-time analytics, large caches). Pick r6idn.2xlarge when it's closer to memory-optimized (memory-bound work — in-memory databases, real-time analytics, large caches). When neither side is obviously right, the cheaper hourly rate usually wins for fault-tolerant batch workloads, while the higher single-core score usually wins for latency-sensitive web traffic. The regional pricing tables linked from each instance page below show where each is currently cheapest — sometimes a >20% regional gap flips the comparison entirely.