AWS m8a.mediumvsAWS m8a.xlarge

m8a.medium pairs 1 vCPUs with 4GB of RAM at $0.0609/hr On-Demand (about $44/mo at 24×7). m8a.xlarge pairs 4 vCPUs with 16GB at $0.2434/hr (~$175/mo). m8a.medium is 300% cheaper per hour than m8a.xlarge ($0.1826/hr gap).

Because both instances are in the **m8a family**, the only thing that changes between them is sizing — same silicon, same architecture (AMD EPYC (x86_64)), same burstable/sustained behavior. The choice is purely about how much capacity you actually need: m8a.medium gives you 1 vCPUs and 4GB of RAM, m8a.xlarge gives you 4 vCPUs and 16GB. 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 m8a.medium delivers ~281% more single-thread Sysbench score per dollar (87479 vs 22954 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 (5242 vs 22012) are what to weigh. Spot pricing flips many of these comparisons — when m8a.medium drops to $0.0205/hr and m8a.xlarge drops to $0.0779/hr, the cheap-per-hour winner can swing meaningfully.

In practice, pick m8a.medium when your workload is closer to general-purpose (balanced general-purpose workloads with a 1:4 vCPU-to-memory ratio). Pick m8a.xlarge 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.