AWS c8g.12xlargevsAWS c8g.16xlarge

c8g.12xlarge pairs 48 vCPUs with 96GB of RAM at $1.9142/hr On-Demand (about $1378/mo at 24×7). c8g.16xlarge pairs 64 vCPUs with 128GB at $2.5523/hr (~$1838/mo). c8g.12xlarge is 33% cheaper per hour than c8g.16xlarge ($0.6381/hr gap).

Because both instances are in the **c8g family**, the only thing that changes between them is sizing — same silicon, same architecture (AWS Graviton (ARM64)), same burstable/sustained behavior. The choice is purely about how much capacity you actually need: c8g.12xlarge gives you 48 vCPUs and 96GB of RAM, c8g.16xlarge gives you 64 vCPUs and 128GB. 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 c8g.12xlarge delivers ~33% more single-thread Sysbench score per dollar (1741 vs 1307 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 (159668 vs 213014) are what to weigh. Spot pricing flips many of these comparisons — when c8g.12xlarge drops to $0.5178/hr and c8g.16xlarge drops to $0.7101/hr, the cheap-per-hour winner can swing meaningfully.

In practice, pick c8g.12xlarge when your workload is closer to compute-optimized (CPU-bound work — batch processing, web servers under sustained load, game servers). Pick c8g.16xlarge 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.