# Memory CL Timing - What is F1 and F2?



## dk777 (Apr 18, 2012)

Hi,
sometimes i am a bit confused when i read a memory-timing like "...8500s 7-10-F2", what's the meaning of the f2 (sometimes its f1)? I know only stuff like cl7-7-7-20, how can i compare the f1 and f2 to the normal ones? Thank u.


Best regards,
dk


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## linkin (Apr 18, 2012)

You mean the Command Rate? It may also be listed as "9-9-9-24-2T" or similar. With the last bit being the Command Rate (the option you will find in the BIOS under memory timings). I'm not sure what it does, exactly.


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## dk777 (Apr 18, 2012)

Nope, there aren't 4 values (CAS-tRCD-tRP-tRAS). This one has just 3 values "7-10-f1" for the timing, that's strange, but some companies use these values instead, its in the specs and its printed on the memory itself. Here is an example: http://imgc.classistatic.com/cps/kjc/120414/615r1/6156faj_20.jpeg


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## linkin (Apr 18, 2012)

Must be a Hynix thing. I don't know.


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## dk777 (Apr 18, 2012)

Nope, i saw the same thing on samsung memory chips  Would be interesting to know, because i wanna buy the right memory for my mac. I also found one with "f3", that's so weird xD Seems like there are 3 different types on the market right now (f1, f2, f3).


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