Memory Latency Calculator – CAS Latency in Nanoseconds
Calculate true memory latency in nanoseconds from CAS latency and frequency.
About This Calculator
Calculate true memory latency in nanoseconds from CAS latency and frequency. Use the calculator above for instant results.
Worked Examples
- tCK = 1000/3200 = 0.3125 ns
- Latency = 16 × 0.3125 × 2 = 10 ns
Answer: 10 ns true latency
- tCK = 1000/5600 = 0.1786 ns
- Latency = 22 × 0.1786 × 2 = 7.86 ns | Better despite higher CL
Answer: 7.86 ns (faster than CL16 DDR4!)
- Latency = 18 × (1000/3600) × 2 = 10 ns
Answer: 10 ns
Who Uses This Calculator?
Compare true latency across RAM kits.
Memory timing optimization.
Accurate latency benchmarking.
Understanding memory specifications.
Common Mistakes to Avoid
❌ CL alone doesn't determine latency
CL16 at 3200 MHz vs CL22 at 5600 MHz: the DDR5 is actually faster in ns! Always calculate true latency.
❌ Latency vs bandwidth tradeoff
You can sometimes trade latency for bandwidth by increasing frequency, which matters for gaming specifically.
Frequently Asked Questions
CAS latency formula?
Latency (ns) = CL × (2000 / frequency_MHz). Or CL × tCK × 2 where tCK = 1000/frequency.
What timings matter?
CAS Latency (CL) is primary. tRCD, tRP, tRAS also matter. All should be as low as possible.
Gaming: latency or bandwidth?
Gaming generally benefits more from lower latency than higher bandwidth. Tight timings at moderate frequency often beat high frequency with loose timings.