Question Difference in tRC . New and old 2x4gb kits.

[makemorelove]

Hello,

Image with red dot is the new ram kit.
Old one has tRC 33 , new one has tRC 41 ?

Shouldn't these numbers be equal ?
Also, I believe I did a successful overclock to 1800mhz ?

I just don't know what these tRC numbers should be set to :\
If anyone can help? Thank you and Merry Christmas.

 

[makemorelove]

Also, I do not have tRC options in my BIOS > Asrock Z77 Extreme3.

 

[makemorelove]

Hello? :/