AWS m8id.2xlargevsAWS m8id.4xlarge

m8id.2xlarge pairs 8 vCPUs with 32GB of RAM at $0.5221/hr On-Demand (about $376/mo at 24×7). m8id.4xlarge pairs 16 vCPUs with 64GB at $1.0442/hr (~$752/mo). m8id.2xlarge is 100% cheaper per hour than m8id.4xlarge ($0.5221/hr gap).

Because both instances are in the **m8id 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: m8id.2xlarge gives you 8 vCPUs and 32GB of RAM, m8id.4xlarge gives you 16 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.

On raw price-per-performance, the two are m8id.2xlarge delivers ~100% more single-thread Sysbench score per dollar (6405 vs 3206 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 (14148 vs 28123) are what to weigh. Spot pricing flips many of these comparisons — when m8id.2xlarge drops to $0.1563/hr and m8id.4xlarge drops to $0.3132/hr, the cheap-per-hour winner can swing meaningfully.

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