AWS c1.mediumvsAWS c1.xlarge

c1.medium pairs 2 vCPUs with 1.7GB of RAM at $0.1300/hr On-Demand (about $94/mo at 24×7). c1.xlarge pairs 8 vCPUs with 7GB at $0.5200/hr (~$374/mo). c1.medium is 300% cheaper per hour than c1.xlarge ($0.3900/hr gap).

Because both instances are in the **c1 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: c1.medium gives you 2 vCPUs and 1.7GB of RAM, c1.xlarge gives you 8 vCPUs and 7GB. 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 c1.medium delivers ~288% more single-thread Sysbench score per dollar (5769 vs 1487 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 (1194 vs 5051) are what to weigh. Spot pricing flips many of these comparisons — when c1.medium drops to $0.0358/hr and c1.xlarge drops to $0.1783/hr, the cheap-per-hour winner can swing meaningfully.

In practice, pick c1.medium when your workload is closer to compute-optimized (CPU-bound work — batch processing, web servers under sustained load, game servers). Pick c1.xlarge 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.