Intel is likely not going to answer that specific (can of worms) question - so I will. Offsetting the voltage positively can have long-term affects on the lifetime of the processor. Offsetting the voltage negatively should not have any long-term affects on the processor - presuming this offset is small enough that it doesn't affect stability.
Hope this helps,
Thank you, N.Scott.Pearson
I do hold the same opinion like yours. But you know,I want an official confirmation(or an adverse opinion against it) from Intel which can eliminates the worries a nd puzzles of me and my colleagues. I and my colleagues are working on laptops,which can boost the performance of cpu through negatively offsetting the voltage of cpu properly. So I'm eager to have a definate answer about it.
Unfortunately, I rather doubt that you will get one. Intel does not officially condone overclocking (and offsetting the voltage is considered overclocking), so they may not be willing to say that this is ok. Still, if you would like to wait for such a response, feel free to do so.