AWS m8gd.largevsAWS m8gd.medium

m8gd.large pairs 2 vCPUs with 8GB of RAM at $0.1153/hr On-Demand (about $83/mo at 24×7). m8gd.medium pairs 1 vCPUs with 4GB at $0.0577/hr (~$42/mo). m8gd.medium is 50% cheaper per hour than m8gd.large ($0.0577/hr gap).

Because both instances are in the **m8gd family**, the only thing that changes between them is sizing — same silicon, same architecture (AWS Graviton (ARM64)), same burstable/sustained behavior. The choice is purely about how much capacity you actually need: m8gd.large gives you 2 vCPUs and 8GB of RAM, m8gd.medium gives you 1 vCPUs and 4GB. 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 m8gd.medium delivers ~91% more single-thread Sysbench score per dollar (28911 vs 55272 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 (6467 vs 3125) are what to weigh. Spot pricing flips many of these comparisons — when m8gd.large drops to $0.0403/hr and m8gd.medium drops to $0.0132/hr, the cheap-per-hour winner can swing meaningfully.

In practice, pick m8gd.large when your workload is closer to general-purpose (balanced general-purpose workloads with a 1:4 vCPU-to-memory ratio). Pick m8gd.medium 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.