Memory voltage

[tino]

I am looking into a 7i-2700k with a Asus P8Z68V-LX and F3-17000CL11D-8GBXL memory. This memory doesn't show In the Asus memory support for this motherboard, and in G-Skill RAM Configurator, this motherboard is not listed.

I have read in this forum that this memory is recommended for this motherboard.

My questions are:
1. What other types of memory can I use for this motherboard?
2. What does it mean when memory is specified at 1.65V? I believe that DDR spec is 1.5V
3. What is the benefit of using XMP type memory? Do I need to use XL, XM, or XH memory with Sandy Bridge?
4. This motherboard specifies DDR3 2133(O.C.). What is O.C.? I know is overclock, but I don't know what it really means (this was asked before in this forum with the answer been overclock).
5. Will two identical sets of two memory sticks work just as well as one set of four memory sticks?

Thanks in advance, Tino.

[Tradesman]

1. Most any DDR3 will work with the mobo, I'd recommend 1600 or better
2. 2133 sticks are high performance and require OCing the CPU/System so many of them require higher than stock 1.5 DDR3 voltage (they are safe as they match up with the higher vCore voltage needed for the OC
3. XMP is basically the standard now on Intel mobos, in efffect, you enable it, select the profile (speed/freq) you want the DRAM to run at and it makes adjustments to the rest of the BIOS to meet min requirements to run at the profile you select.
4. Just as an example, to run 2133 sticks the rest of the system has to be running at an equal or greater speed, the 2600K is rated at 3.4 GHz, so it may require your CPU to be OCed to say 4.2 GHz to run the sticks (which basically is just raising the CPU multiplier to 42) the 2600K with a good aftermarket heatsink should be able to run 4.8-5 GHz on air.
5. A set of 4 sticks is recommended as they are tested to work together, two sets can become problematic, especially if purchased at different time and with higher end sticks for a number of reasons, (may be from different production lots, or made of different lots of PCBs, ICs, etc), generally if they won't play together, you can get them to with voltage/timing adjustments, but the higher end the sticks, the harder it can be and at times the sets just won't play together

Hope this helps, if any further questions, I'll be in and out over the weekend

[tino]

Thanks for your fast and very informative replay. I still I am unclear about memory voltage.

DDR3 2133 memory specified at 1.5V is better (faster) then one specified at 1.65V?

[Tradesman]

A lot of it depends on the actual chips used, generally (but not always) the 1.5 sticks will run native at a higher CL (CAS Latency) i.e. 11, vs ones with tighter (CL9 or CL10) timings which are higher performance and require a bit more voltage.