AWS i3.largevsAWS i3.xlarge

i3.large pairs 2 vCPUs with 15.3GB of RAM at $0.1560/hr On-Demand (about $112/mo at 24×7). i3.xlarge pairs 4 vCPUs with 30.5GB at $0.3120/hr (~$225/mo). i3.large is 100% cheaper per hour than i3.xlarge ($0.1560/hr gap).

Because both instances are in the **i3 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: i3.large gives you 2 vCPUs and 15.3GB of RAM, i3.xlarge gives you 4 vCPUs and 30.5GB. 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 i3.large delivers ~408% more single-thread Sysbench score per dollar (14750 vs 2901 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 (2742 vs 2643) are what to weigh. Spot pricing flips many of these comparisons — when i3.large drops to $0.0412/hr and i3.xlarge drops to $0.1456/hr, the cheap-per-hour winner can swing meaningfully.

In practice, pick i3.large when your workload is closer to storage-optimized (NVMe SSD) (I/O-bound work needing low-latency NVMe local storage — NoSQL, search). Pick i3.xlarge when it's closer to storage-optimized (NVMe SSD) (I/O-bound work needing low-latency NVMe local storage — NoSQL, search). 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.