What is latency and timing?

[Nate_88]

I am curious what is latency and timing when it comes to memory?
What does it effect? Is there "good" or "better" latency or timing?

Thanks

 

[rolli59]

The lower the number the faster the ram operates. http://en.wikipedia.org/wiki/SDRAM_latency

 

[jaquith]

Short, but pertinent answer:

Latency is the LAG between the IMC 'call' and the RAM 'output' - http://en.wikipedia.org/wiki/CAS_latency

Timing best analogy is 'like' accessing an Excel Spread Sheet {CL-Find, TRCD-Accessing Row/Column, TRP-Accessing Next, and TRAS-Total Time}. CL, TRCD, TRP, TRAS http://en.wikipedia.org/wiki/Memory_timings

Next understanding how Latency & Timing are related which is inversely to increased Frequency {Sine Wave}. Further, efficiency through Lithography {e.g. 32nm or less - less is better}, Voltage {good correlation with Lithography} and Lower Operational Temperatures {increased stability}. To confuse it more, the true measure is a good quality and efficient IC; LOOKING at timings/frequency doesn't provide the 'Answer' what's faster. To KNOW you need to Bench Test with Apps like Super PI.

The initial identification of Good RAM is High Frequency {Fast} with Low CAS {Fast} and the efficiency with Low-Tight CAS Timings. Tight - 8-8-8; Loose = 7-8-7. Often the Mfg's go for a low CL in sacrificing TRCD which may or may not be faster, again the Bench Test.