AWS r8i.8xlargevsAWS r8i.metal-48xl

r8i.8xlarge pairs 32 vCPUs with 256GB of RAM at $2.2227/hr On-Demand (about $1600/mo at 24×7). r8i.metal-48xl pairs 192 vCPUs with 1536GB at $13.3363/hr (~$9602/mo). r8i.8xlarge is 500% cheaper per hour than r8i.metal-48xl ($11.1136/hr gap).

Because both instances are in the **r8i 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: r8i.8xlarge gives you 32 vCPUs and 256GB of RAM, r8i.metal-48xl gives you 192 vCPUs and 1536GB. 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 3319/56009 for r8i.8xlarge and pending for r8i.metal-48xl. 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 r8i.8xlarge when your workload is closer to memory-optimized (memory-bound work — in-memory databases, real-time analytics, large caches). Pick r8i.metal-48xl 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.