What are the Intel® Core™ i7 processor and the Intel® Core™ i5 processor DDR3 memory voltage limitations? Intel® recommends using memory that adheres to the Jedec memory specification for DDR3 memory which is 1.5 volts, plus or minus 5%. Anything over this voltage can either damage the processor or significantly reduce the processor life span.
What is the maximum frequency for DDR3 memory when used with Intel® Core™ i7-900 processor series? These processors support DDR3 memory with a maximum frequency of 1066 MHz. If faster DDR3 memory is used (such as 1333 MHz or 1600 MHz), it will be down-clocked to operate at 1066 MHz.
What is the maximum frequency for DDR3 memory when used with Intel® Core™ i7-800 processor series and the Intel® Core™ i7-700 processor series? These processors support DDR3 memory with a maximum frequency of 1333 MHz. If faster DDR3 memory is used (such as 1600 MHz or higher), it will be down-clocked to operate at 1066 MHz.
That said, there's plenty people running 1.65 memory at high speeds, for no reason! If you'll take a look here: http://www.tomshardware.com/reviews/memory-scaling-i7,2...
you'll see that there is no appreciable difference between actual performance levels of overclocked RAM... And, I'm pretty sure, all the fast stuff is actually over-volted over-clocked JEDEC standard DDR3-1066 1.5V at heart... I'm trying to hunt down reliable specs, but it seems to have become unfashionable to provide actual documentation for RAM, as evidenced by this lovely Corsair doc: http://www.corsair.com/_datasheets/TW3X4G1333C9.pdf
I have seen 10%+ increase moving from DDR3 1066 7-7-7 to DDR3 1600 7-7-7. Timings are key.
Are you trying to say that running DDR3 1600 @ QPI voltage 1.30v and RAM voltage of 1.60v will shorten the lifespan of an i7??? Intel's stated maximum QPI voltage is 1.355v and almost all of this high speed low-latency is rated at 1.65v but will actually run at 1.60v. Sorry but it feels like fear mongering to tell people that running at these specs will damage their processor.
I will take the 10% speed increase any day. 1.3v QPI and 1.6v RAM is plenty safe. Overclock at will!
I have seen 10%+ increase moving from DDR3 1066 7-7-7 to DDR3 1600 7-7-7
You are comparing apples to orangutangs here. That 1066 7-7-7(RAM 'A'), assuming it will run at 1600, will need to run at 1600 10-10-10, or 11-11-11; conversely, the 1600 7-7-7(RAM 'B') will run at 1066 5-5-5 (and maybe, at 5-4-5, or 5-4-4); either way, even if comparing RAM A at 1600 with RAM B at 1066 (and 5-5-5), RAM B will be a lot faster - but there won't be an appreciable difference between RAM B at 1600 7-7-7, and RAM B at 1066 5-5-5... (And there will be an attendant increase in power consumption, current through the memory controller, and heat dissipation all around at 1600)