AWS m8i-flex.2xlargevsAWS m8id.2xlarge

m8i-flex.2xlarge pairs 8 vCPUs with 32GB of RAM at $0.4022/hr On-Demand (about $290/mo at 24×7). m8id.2xlarge pairs 8 vCPUs with 32GB at $0.5221/hr (~$376/mo). m8i-flex.2xlarge is 30% cheaper per hour than m8id.2xlarge ($0.1199/hr gap).

Both are generation-8 general-purpose instances, but they run on different silicon: **m8i-flex.2xlarge** is Intel Xeon (x86_64), **m8id.2xlarge** is Intel Xeon (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.

On raw price-per-performance, the two are m8i-flex.2xlarge delivers ~29% more single-thread Sysbench score per dollar (8289 vs 6405 points per $1/hr). That's the cleanest signal we have for "which one runs your workload faster per dollar," but it only matters if your workload is single-thread-bound; for parallel workloads the multi-core scores (14030 vs 14148) are what to weigh. Spot pricing flips many of these comparisons — when m8i-flex.2xlarge drops to $0.1385/hr and m8id.2xlarge drops to $0.1563/hr, the cheap-per-hour winner can swing meaningfully.

In practice, pick m8i-flex.2xlarge when your workload is closer to general-purpose (balanced general-purpose workloads with a 1:4 vCPU-to-memory ratio). Pick m8id.2xlarge 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.