AWS c6i.16xlargevsAWS c6in.24xlarge

c6i.16xlarge pairs 64 vCPUs with 128GB of RAM at $2.7200/hr On-Demand (about $1958/mo at 24×7). c6in.24xlarge pairs 96 vCPUs with 192GB at $5.4432/hr (~$3919/mo). c6i.16xlarge is 100% cheaper per hour than c6in.24xlarge ($2.7232/hr gap).

Both are generation-6 compute-optimized instances, but they run on different silicon: **c6i.16xlarge** is Intel Xeon (x86_64), **c6in.24xlarge** is Intel Xeon (x86_64). AMD variants (suffix `a`) are typically 10% cheaper than Intel siblings at comparable single-thread performance. Graviton variants (suffix `g`) are usually 20–40% cheaper but require ARM64-compatible binaries — most modern Linux stacks are fine, but verify any compiled extensions, native modules, or third-party binaries before migrating. Same vCPU/RAM ratio, same network performance class, different processor.

On raw price-per-performance, the two are c6i.16xlarge delivers ~99% more single-thread Sysbench score per dollar (1088 vs 547 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 (99154 vs 148602) are what to weigh. Spot pricing flips many of these comparisons — when c6i.16xlarge drops to $0.8104/hr and c6in.24xlarge drops to $1.4005/hr, the cheap-per-hour winner can swing meaningfully.

In practice, pick c6i.16xlarge when your workload is closer to compute-optimized (CPU-bound work — batch processing, web servers under sustained load, game servers). Pick c6in.24xlarge 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.