AWS m4.10xlargevsAWS m4.2xlarge

m4.10xlarge pairs 40 vCPUs with 160GB of RAM at $2.0000/hr On-Demand (about $1440/mo at 24×7). m4.2xlarge pairs 8 vCPUs with 32GB at $0.4000/hr (~$288/mo). m4.2xlarge is 80% cheaper per hour than m4.10xlarge ($1.6000/hr gap).

Because both instances are in the **m4 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: m4.10xlarge gives you 40 vCPUs and 160GB of RAM, m4.2xlarge gives you 8 vCPUs and 32GB. 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 m4.2xlarge delivers ~390% more single-thread Sysbench score per dollar (508 vs 2490 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 (31205 vs 6246) are what to weigh. Spot pricing flips many of these comparisons — when m4.10xlarge drops to $0.6042/hr and m4.2xlarge drops to $0.1649/hr, the cheap-per-hour winner can swing meaningfully.

In practice, pick m4.10xlarge when your workload is closer to general-purpose (balanced general-purpose workloads with a 1:4 vCPU-to-memory ratio). Pick m4.2xlarge 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.