A couple weeks ago I sent this question up to engineers to answer about the voltage if users can use 1.65v without any problems. The response that I got back was that it is possible to use the 1.65v memory but it is really pushing more stress on the processor’s memory controller then we would like and that if our Tech support finds out about you using memory at this voltage it can void the warranty. Now there maybe some setting in the Bios on a board that you can change the memory voltage down to 1.5v but I would rather tell you right off the bat to avoid it since most memory makers are offering both at the same price. Leaps-from-Shadows does a good job of covering this issue.
Christian Wood
Intel Enthusiast Team
Truth be said, I see a lot more 'problems' with 1.50V RAM + SB. The link essentially says what I've stated, I too read both sets of Intel specs. I bought into the 1.65 'bad' until logic and documentation proved otherwise.
1.5v ram is what you want for P67. You can use 1.65v ram however, but I wouldn't recommend that if your overclocking at all. Anything over 1.65v can damage the cpu.
I've not seen even one, out of hundreds of P67/H67/H61 that has a problem with 1.5v ram if the timings and speed is manually set correctly. Nor have I seen a single problem with 1.65v ram if the speed and timings are manually set correctly. However, Intel still recommends 1.6v max. Only time will tell if these overclockers start having cpu failures.
1.65v RAM is allowable on Sandy Bridge motherboards
If you go strictly on Intel spec voltage then an most CPU OC would be impossible. DRAM Voltage up to 1.575v is 100% within spec.
After putting my nose into Intel's CPU manuals the LGA 1156, LGA 1366 {i7-900, i7-800, & i5-700} and LGA 1155 {i7, i5 and i3} ALL had the SAME "DDR3 I/O Voltage of 1.5 V" and SAME DRAM Voltage up to 1.575v.
However, if the RAM is 1.65v then 1.65v will be set in the BIOS. It has been proven the 1.65v is 'Urban Myth' to be harmful to P67/Z68 SB CPUs.
Therefore, this is all becoming more and more 'Urban Myth' that 1.65v RAM is 'bad' for the Sandy Bridge.
Ok I'll try those, thanks. but my HDD is already using a sata2 port. does XMP mode for memory mean the memory will run at a voltage higher than 1.5?