AWS m8a.16xlargevsAWS m8azn.3xlarge

m8a.16xlarge pairs 64 vCPUs with 256GB of RAM at $3.8950/hr On-Demand (about $2804/mo at 24×7). m8azn.3xlarge pairs 12 vCPUs with 48GB at $1.2388/hr (~$892/mo). m8azn.3xlarge is 68% cheaper per hour than m8a.16xlarge ($2.6563/hr gap).

Both are generation-8 general-purpose instances, but they run on different silicon: **m8a.16xlarge** is AMD EPYC (x86_64), **m8azn.3xlarge** is AMD EPYC (x86_64). 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 m8a.16xlarge and 6201/74658 for m8azn.3xlarge. 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 m8a.16xlarge when your workload is closer to general-purpose (balanced general-purpose workloads with a 1:4 vCPU-to-memory ratio). Pick m8azn.3xlarge when it's closer to general-purpose (balanced general-purpose workloads with a 1:4 vCPU-to-memory ratio). 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.