AWS is4gen.largevsAWS is4gen.xlarge

is4gen.large pairs 2 vCPUs with 12GB of RAM at $0.2882/hr On-Demand (about $207/mo at 24×7). is4gen.xlarge pairs 4 vCPUs with 24GB at $0.5763/hr (~$415/mo). is4gen.large is 100% cheaper per hour than is4gen.xlarge ($0.2882/hr gap).

Because both instances are in the **is4gen family**, the only thing that changes between them is sizing — same silicon, same architecture (arm64), same burstable/sustained behavior. The choice is purely about how much capacity you actually need: is4gen.large gives you 2 vCPUs and 12GB of RAM, is4gen.xlarge gives you 4 vCPUs and 24GB. 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 is4gen.large delivers ~100% more single-thread Sysbench score per dollar (9738 vs 4876 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 (5362 vs 10974) are what to weigh. Spot pricing flips many of these comparisons — when is4gen.large drops to $0.0828/hr and is4gen.xlarge drops to $0.1922/hr, the cheap-per-hour winner can swing meaningfully.

In practice, pick is4gen.large when your workload is closer to general-purpose (general-purpose workloads). Pick is4gen.xlarge when it's closer to general-purpose (general-purpose workloads). 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.