AWS r8g.metal-48xlvsAWS r8gn.metal-24xl

r8g.metal-48xl pairs 192 vCPUs with 1536GB of RAM at $11.3107/hr On-Demand (about $8144/mo at 24×7). r8gn.metal-24xl pairs 96 vCPUs with 768GB at $8.7446/hr (~$6296/mo). r8gn.metal-24xl is 23% cheaper per hour than r8g.metal-48xl ($2.5661/hr gap).

Both are generation-8 memory-optimized instances, but they run on different silicon: **r8g.metal-48xl** is AWS Graviton (ARM64), **r8gn.metal-24xl** is AWS Graviton (ARM64). AMD variants (suffix `a`) are typically 10% cheaper than Intel siblings at comparable single-thread performance. Graviton variants (suffix `g`) are usually 20–40% cheaper but require ARM64-compatible binaries — most modern Linux stacks are fine, but verify any compiled extensions, native modules, or third-party binaries before migrating. Same vCPU/RAM ratio, same network performance class, different processor.

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 r8g.metal-48xl and 3337/319549 for r8gn.metal-24xl. 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 r8g.metal-48xl when your workload is closer to memory-optimized (memory-bound work — in-memory databases, real-time analytics, large caches). Pick r8gn.metal-24xl 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.