CAS Latency higher than RAM specs


Nov 3, 2011
I recently had some games stuttering because my memory (most likely) or GPU RAM was running out. I only had 2x2GB, so I decided to upgrade to 4x2GB. The site where I originally bought my memory showed it as Kingston KHX1333C7D3K2/4G, so naturally I got another kit of that. Now, it should be running at 1333MHz with a CL of 7, but CPUz and my BIOS show that though the frequency is fine and the full 8 GB is recognised, the latency is 9. I don't know why it does that: I haven't overclocked nor done anything else to change automatic or default settings. However, CPUz recognised my original memory as 9905403-115.A00LF instead of KHX1333C7D3K2 (as my new memory is listed). Also, CPUz shows XMP-1334 where it shows only JEDEC for my old memory...

EDIT: I just discovered that though the EDIT function doesn't work, the Quick Edit function does allow me to edit my posts. I don't understand that, but whatever.
I did some more homework, and discovered that my memory runs by default at JEDEC standards (CL7, 1.5V), but that Kingston likes to market the XMP standard, which is a lower latency at the cost of a higher voltage. I found the XMP function under "AI Overclock Tuner" in my BIOS.
Now, it seems enabling XMP is considered overclocking by your Motherboard, but since my DRAM frequency is 1333MHz either way my CPU BCLK frequency shouldn't change. The only effective change should be a lower RAM CAS Latency and a higher RAM voltage. Can anyone more experienced than me tell me whether there are also other (negative) consequences that I don't know of and whether this will void the warranty or not? Since Kingston advertises the XMP values themselves, I wouldn't expect that to be the case, but still a second opinion would be appreciated.

(CPU: Intel i5 750, Mobo: ASUS P7P55D)