AWS i3.xlargevsAWS i7i.xlarge

i3.xlarge pairs 4 vCPUs with 30.5GB of RAM at $0.3120/hr On-Demand (about $225/mo at 24×7). i7i.xlarge pairs 4 vCPUs with 32GB at $0.3775/hr (~$272/mo). i3.xlarge is 21% cheaper per hour than i7i.xlarge ($0.0655/hr gap).

These are different generations of the same series. **i7i.xlarge** is the newer generation, and AWS's pattern across generations is fairly consistent: ~10–15% better single-thread, 15–30% better multi-core, and similar or modestly higher per-hour pricing — so the price/performance per dollar usually improves with each generation. **i3.xlarge** is still available and still works (AWS doesn't retire instance types quickly), but for new workloads the newer generation is typically the better default unless you have a specific reason to pin to the older AMI or there's a meaningful regional pricing advantage today.

On raw price-per-performance, the two are i7i.xlarge delivers ~211% more single-thread Sysbench score per dollar (2901 vs 9012 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 (2643 vs 6973) are what to weigh. Spot pricing flips many of these comparisons — when i3.xlarge drops to $0.1495/hr and i7i.xlarge drops to $0.1171/hr, the cheap-per-hour winner can swing meaningfully.

In practice, pick i3.xlarge when your workload is closer to storage-optimized (NVMe SSD) (I/O-bound work needing low-latency NVMe local storage — NoSQL, search). Pick i7i.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.