The "Performance-optimized Compute Unit" suits low latency or high throughput similarity searches. This option works best for high-search performance scenarios.
The "Capacity-optimized Compute Unit" serves data volumes that are five times larger than the performance-optimized CU option. This option works best for increased storage capacity scenarios.
The "Cost-optimized Compute Unit" provides the same large capacity as the "Capacity-optimized" option, but at a lower cost. This option is ideal for budget-conscious projects that need ample storage without high-performance demands.
For more details, see Select the Right CU.