How to use it
- Enter the effective data rate in MT/s.
- Enter the CAS latency value.
- Calculate to see theoretical first-word latency.
RAM Speed Calculator
Convert RAM data rate and CAS latency into first-word latency.
About the RAM Speed Calculator
Compare memory kits by translating advertised MT/s and CAS latency into a theoretical first-word delay in nanoseconds.
Latency formula
First-word latency in nanoseconds = CAS latency × 2,000 ÷ data rate in MT/s.
Example
DDR memory rated at 6000 MT/s with CL30 has a theoretical first-word latency of 10 ns.
Notes
This single timing does not represent total memory performance. CPU memory controller, subtimings, channel configuration and workload also matter.