More on Intel’s mid-range overclock lock
Bloomfield, the high-end sort, will sport an internal QPI (QuickPath Interconnect) controller, which will be used to overclock the processor. The frequency of the QPI controller will be the reference through which memory and clock frequency will be calculated via dividers. The frequency of the QPI controller is in turn controlled by manipulating the PLL inside the Tylersbyrg/X58 northbridge. The way we’re used to do things, more or less.
Lynnfield and Havendale lacks the QPI controller, and the northbridge PLL has been moved on-die, which makes it hard to find any real means for altering the clock frequency, IF the PLL is locked, which we can’t be certain it is. Fudzilla also states that there is a second PLL which acts as a roadblock for anyone who wants to overclock. We haven’t seen or heard of anything like that. With lack of inside information on the exact structure of the mid-range Nehalem chips, we can’t be certain of anything right now, but looking at the architecture we can only conclude that overclocking will be different, but there’s not much saying it will be impossible.