AWS c7i.16xlargevsAWS c7i.8xlarge

c7i.16xlarge pairs 64 vCPUs with 128GB of RAM at $2.8560/hr On-Demand (about $2056/mo at 24×7). c7i.8xlarge pairs 32 vCPUs with 64GB at $1.4280/hr (~$1028/mo). c7i.8xlarge is 50% cheaper per hour than c7i.16xlarge ($1.4280/hr gap).

Because both instances are in the **c7i 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: c7i.16xlarge gives you 64 vCPUs and 128GB of RAM, c7i.8xlarge gives you 32 vCPUs and 64GB. 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.

Benchmark data for at least one of these instances is still being collected, so a direct performance-per-dollar comparison isn't possible yet. Sysbench scores are pending for c7i.16xlarge and 3284/53822 for c7i.8xlarge. Check back as the benchmark queue completes — newer-generation instances typically score 10–30% higher on single-thread and 15–50% higher on multi-core vs the previous generation in the same series.

In practice, pick c7i.16xlarge when your workload is closer to compute-optimized (CPU-bound work — batch processing, web servers under sustained load, game servers). Pick c7i.8xlarge when it's closer to compute-optimized (CPU-bound work — batch processing, web servers under sustained load, game servers). 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.