Efficiency: Single-Threaded (One Core Active)
The above chart shows the total time for running all of our single-threaded benchmarks. As a result, the only clock rates that apply are the ones on the right-hand side of the Turbo Boost frequencies, from 3.9 to 4.7 GHz. The maximum overclock saved time to the tune of 16%, but clock rate had to increase by more than 20% in order to get there.
The average amount of energy required for the operation climbed by a more staggering 40% or so.
Because we don't test with a ton of single-threaded software, our scripted benchmark doesn't take long to complete. The total energy requirement at stock clocks was just 7.2 Wh. The most aggressive overclock came in at 8.3 Wh. Multiply those numbers out over hours, days, weeks, and months, though, and you get a better sense for how this could impact your power bill.
Nice to know Intel doesn't just set the stock clock speed for just performance!
Did someone at Intel tell you that was the reason for a lower Turbo Boost limit, or did you just assume it?
I think we should be careful of this kind of guess at another person's, or company's, reasoning. There could be some other cause for the limit - for example, they will obviously sell it for a lower price, so wouldn't a possible reason be they have looser binning specs to allow for chips that wouldn't make it under more strenuous tests through? (Remember, Intel, or any CPU manufacturer, doesn't warrant the product based on what it can be pushed to, and is generally going to provide it at a clock rate they feel is safe over time to guarantee.)
I'm certainly not saying it is a bad assumption, what you said makes sense to me, but I do think there are enough other reasonable possibilities that I wouldn't have stated it as a fact unless I knew it to be.
I do think articles like this are very important; those of us who overclock, especially when we turn off all the power-saving features in hopes of reaching that max stable a CPU can do, should be aware of how much money we are spending if we keep said OC. It's more than just the high end cooling solution.
The people that bash higher capacity PSUs could also stand to learn a thing or two, here. An overclocked CPU can require a huge amount of peak power over and above what a stock CPU needs (349W measured here). An overclocked Sandy Bridge-E and an overclocked GTX 580 could require a peak power of 650W just considering those 2 components!
A Kill A Watt or similar device is a great way to measure how much you actually spend a month operating your computer. You might be surprised.
Tom's Parallel Universe Hardware.