Corsair LPX 16GB - XMP profiles/performance?


Jan 27, 2015
I Have,

Corsair Vengeance LPX DDR4 16GB Kit 2666Mhz CL16
Density: 16GB (4x4GB)
Speed: 2666MHz
Tested Latency: 16-18-18-35
Voltage: 1.2V
Format: DIMM

Am I understanding this correctly that all DDR4 initially starts at a "safe" speed - somewhere around 2166mhz and you need to use the XMP profiles to get the better speeds. I read somewhere that once you hit over 2600 mhz some mobos automatically increase the blck to 125 which could cause problems with any current cpu overclock so it may be best to run the CPU at stock speeds while testing RAM with the XMP profiles?

Would anyone have any idea of performance gain between say 2166mhz and the 2666 or even 2800 XMP profiles?

I've only had the kit a few days and limited time to play with it so I'm guessing someone else here has been through something similar and could give me some indication of performance increases (or not) as the case may be?!

[strike]That is incredibly SLOW memory.

Look up on the top row of articles here on Toms, and you will see an article on memory.

In that article, he lists memory speed, and the timings you would like to have with them.

Want to get ahead of the game? Look for a good combination of the two, like this:

1600/7 1866/8 2133/9 2400/10 2666/11 2800/12

Your memory shows:

Speed: 2666MHz
Tested Latency: 16-18-18-35

My suggestion. Return the memory and get some with timings of 11, or get slower memory that matches his list.

Keep in mind that after 1866 speed memory, there is almost no improvement even at 2133, and then none after that. So spending money to buy high speed memory like that is wasting money. I know. I bought a 2667 kit. And after testing it thoroughly I wish I had just gotten 1866 memory.[/strike]


Legenda in Aeternum


Thanx for that, have rec'd a number of comments on it and even more PMs about it, Part 2 is due out on the 17th and to me, the more interesting part, it looks at a number of myths and further explains a number of other points often taken out of context
I've been building machines since the late 1980's, and even ran my own company for over 12 years building computers and servers, writing custom programs for companies, training their staff on how to use the system, and educating management on reports and other things.

And even with all that experience, there were things I had never known for certain that were in your article. I know there is so much that I do not know when it comes to computers. I know a lot, but in helping people in the forums here, I learn at least 1 new thing a day, then the articles like yours add to that. So thank you for what you wrote.