Originally Posted by Kougar
You need to understand that by default, RAM will run at official JEDEC timings for compatibility reasons. It's a universal standard for PCs, as if the user buys higher performance RAM then they can modify the appropriate settings to get the performance.
If you want to run your RAM outside that spec you need to do so manually by either changing the settings yourself or by selecting XMP in your BIOS. You have either option, but XMP is easier since it automatically adjusts subtimings to match the lower CL timing.
The reason they do this is simple... imagine if you bought two of those memory kits. If the motherboard defaulted to XMP then odds are your system wouldn't even boot, or it could boot with unstable RAM. The XMP profile does not take into account if you are running double the memory modules the profile timings were created for. My system can't even boot if I use the XMP profile because I'm running two high-performance kits, but it boots fine on the default memory profile. There's other considerations such as RAM voltages and the CPU's memory controller rating and still other factors that can affect RAM stability as well, which is why by default motherboards automatically use the JEDEC profiles unless told otherwise.
Thank you for your reply.. So basically it is my mainboard reading my RAM's JEDEC settings preventing it from running at CL7@1333Mhz and not the ram itself.. That's good news since I plan to build a new system in the future which is the main reason i went with the more expensive ram. Also I can't run XMP since I'm running an AMD setup. Which is one thing that worried me about the XMP JEDEC settings in CPU-z. So thank you for clarifying the confusion I had.