AWS m3.2xlargevsAWS m3.xlarge

m3.2xlarge pairs 8 vCPUs with 30GB of RAM at $0.5320/hr On-Demand (about $383/mo at 24×7). m3.xlarge pairs 4 vCPUs with 15GB at $0.2660/hr (~$192/mo). m3.xlarge is 50% cheaper per hour than m3.2xlarge ($0.2660/hr gap).

Because both instances are in the **m3 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: m3.2xlarge gives you 8 vCPUs and 30GB of RAM, m3.xlarge gives you 4 vCPUs and 15GB. 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 m3.xlarge delivers ~101% more single-thread Sysbench score per dollar (1957 vs 3925 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 (6332 vs 3154) are what to weigh. Spot pricing flips many of these comparisons — when m3.2xlarge drops to $0.2012/hr and m3.xlarge drops to $0.0927/hr, the cheap-per-hour winner can swing meaningfully.

In practice, pick m3.2xlarge when your workload is closer to general-purpose (balanced general-purpose workloads with a 1:4 vCPU-to-memory ratio). Pick m3.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.