RAM performance metrics: Which RAM timing parameters most directly determine the memory's operating speed in sustained operation (read and write cycles)?

Introduction / Context:
Memory speed is not only about access time (address-to-data). In practical systems, the cycle time—how quickly consecutive reads or writes can be initiated—sets the sustainable bandwidth. Therefore, parameters like read cycle time (t_rc) and write cycle time (t_wc) are central to overall performance.

Given Data / Assumptions:

• t_acc (or t_AA) is address access time for a single read event.
• t_rc and t_wc define minimum time between successive read and write operations.
• We consider generic asynchronous SRAM/DRAM nomenclature; exact names vary by vendor but the concepts are consistent.

Concept / Approach:
While a fast t_acc yields quick first-data latency, the maximum transaction rate depends on the minimum cycle times. If t_rc or t_wc are long, a fast t_acc cannot raise sustained throughput. Thus, operating speed (in continuous bursts of operations) is determined by cycle times for reads and writes.

Step-by-Step Solution:

Verification / Alternative check:
Throughput calculations use 1 / t_rc (reads) or 1 / t_wc (writes) for maximum operation rate. Timing diagrams explicitly show these as the cadence limits for back-to-back cycles.

Why Other Options Are Wrong:

• tacc only: Important for latency, insufficient to define sustained speed.
• taa and tacs, t1 and t3: Nonstandard or incomplete labels; do not by themselves define cycle cadence.

Common Pitfalls:
Optimizing for t_acc while ignoring cycle time constraints; the system appears fast for a single read but underperforms in continuous transfers.

Final Answer:
trc and twc