For an Intel(R) Core(TM) i7-2600K Processor, the supported memory voltage is 1.5v.:
As for overclocking, just wanted to indicate that the operation of any Intel-manufactured product outside the published specifications for each part can result in data corruption and unreliable system behavior. For further details regarding overclocking, please, refer to the following website:
Thanks Salem_Intel for those links. I was running in circles on the Intel site, Lol.
My reason for asking about the memory voltage was that I did buy some 1.5v sticks but that doesn't leave much room for overclocking. Though, to be honest I've never really oc'ed anything before so what do I know. I was thinking of sending the 1.5v sticks back and buying some 1.35v RAM. However, will 1.35v RAM work OK? I ask because it is out of the + or - 5% range. The motherboard I'm using is an ASUS P8Z68-V PRO. I've browsed the board's qualified vendor list of RAM that should work with the board. Most of the RAM in the list shows 1.65v which is a bit beyond the +5% limit.
Even though the Asus* P8Z68-V PRO may support memory voltages of up to 1.65V, processor-wise, as the CPU itself is not tolerant to higher than 1.5v., it's recommended using 1.5v. Should you have a 1.65v. memory and this one features Intel Extreme Memory Profile (Intel XMP) that you can "play with" in the BIOS of your board, although this would still be customization, you may want to check with your memory manufacturer for instructions on how to make use of XMP. As for Intel, it recommends using memory that adheres to the Jedec memory specification for DDR3 memory which is 1.5 volts, plus or minus 5%.