AWS r8gb.8xlargevsAWS r8gb.xlarge

r8gb.8xlarge pairs 32 vCPUs with 256GB of RAM at $2.9149/hr On-Demand (about $2099/mo at 24×7). r8gb.xlarge pairs 4 vCPUs with 32GB at $0.3644/hr (~$262/mo). r8gb.xlarge is 87% cheaper per hour than r8gb.8xlarge ($2.5505/hr gap).

Because both instances are in the **r8gb 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: r8gb.8xlarge gives you 32 vCPUs and 256GB of RAM, r8gb.xlarge gives you 4 vCPUs and 32GB. 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 r8gb.xlarge delivers ~700% more single-thread Sysbench score per dollar (1143 vs 9142 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 (106454 vs 13147) are what to weigh. Spot pricing flips many of these comparisons — when r8gb.8xlarge drops to $0.5048/hr and r8gb.xlarge drops to $0.1361/hr, the cheap-per-hour winner can swing meaningfully.

In practice, pick r8gb.8xlarge when your workload is closer to memory-optimized (memory-bound work — in-memory databases, real-time analytics, large caches). Pick r8gb.xlarge when it's closer to memory-optimized (memory-bound work — in-memory databases, real-time analytics, large caches). 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.