Overclocking Core i7-3770K: Learning To Live With Compromise

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We recently took our first look at Intel's Ivy Bridge architecture. Then, we evaluated its efficiency. Now, we turn to overclocking. Recently, each of Intel's die shrinks has helped increase frequency headroom. This time, however, we ran into some walls.

Ivy Bridge Takes A Bronze In Overclocking; Gold In Efficiency

We're not going to mince words here. The new Ivy Bridge-based processors manufactured at 22 nm serve up high performance and moderate power consumption. They can be overclocked to respectable levels. With that said, though, Intel's preceding generations helped facilitate impressive overclocking, and our expectations for this generation were higher. The first retail CPUs employing the Ivy Bridge architecture cannot be overclocked as well as their predecessors on conventional air cooling. However, the difference in attainable clock rate translates to similar performance when you compare to the fastest Sandy Bridge-based chips.

In Practice There Are Clear Frequency Limits

The small die size of Ivy Bridge turns into a mixed blessing. Packing four cores, a more complex GPU, and 8 MB L3 cache into a mere 160 mm2, the new chip occupies 26% less area than a comparable Sandy Bridge CPU. Disregarding the GPU, which is bigger now than, the CPU shrinks by approximately 40%.

Intel counters the smaller die by dropping Ivy Bridge's thermal ceiling. Overclocked, though, Ivy Bridge must dissipate close to the same heat as a Sandy Bridge-based CPU, but across less surface area. It is pretty clear that Intel's decision to use thermal paste instead of thermally-conductive solder puts a vice on the frequencies this CPU can stably achieve. The end result is a more pronounced and rapid thermal ramp-up that can only be effectively addressed using more aggressive cooling solutions. In a nutshell, for an average system builder, there are clear limits to overclocking Ivy Bridge. We will have to wait and see if future products from Intel employ better material between the processor die and heat spreader.

Clear Real-World Advantages

With all things considered, despite its limited overclocking potential, Core i7-3770K is only slightly slower than the 32 nm Core i7-2600K with both CPUs pushed as far as they can go. In practice, the difference isn't noticeably, though.

At idle and under load, though, the Ivy Bridge-based chip draws significantly less power. Power users satisfied with frequencies under 4.5 GHz can get great performance with low power use from a Core i7-3770K. But the recommendation we made in our launch story stands: this isn't worth an upgrade if you followed our advice last year and bought a fast Sandy Bridge-based chip. Really, it's only the right move for folks stuck on platforms more than a generation old.

Patrick Schmid
143 Comments Comment from the forums
  • mayankleoboy1
    Nice review!

    1. Are there plans to release any K CPU's without the HD4000? will they OC higher?

    2. Any chance of intel releasing a second stepping of K-series IB chips?
    Reply
  • mayankleoboy1
    i agree that SB chips spoiled the OC world by making OC so easy and fruitful. IB has nothing to compare it to except SB.
    Reply
  • vilenjan
    Good old Intel. No competition and look what happens, the new generation is barely an upgrade over the previous. Anyone remember Intel PII 450s and the PIII 450s?
    Reply
  • ta152h
    I'm not sure why the reviewers spent so much time figuring out the shrink made the core more dense, and somehow thought this was significant. I mean, really, this happens virtually every shrink, and this time the power dropped more than normal. Common sense should be telling people this is not the cause, but somehow people aren't understanding this.

    It's very interesting that replacing the paste makes so much difference. This is obviously something Intel is aware of, since they do plenty of testing, and obviously chose anyway. Would a few pennies be worth it for a processor that is clearly on the higher end of the scale? Probably not.

    Most likely, they want to keep selling their real high end processors, and it just won't do to have the 3770K beating their 2011 processors, or being very competitive with the successors to that line when they come out. It makes perfect sense. The 3770K is still a great processor, but if you're really looking for the best, it simply will not do. You're forced to buy the more expensive 3960X, and later the even better IB successor to it, which you can bet will have far better paste, and so will overclock significantly better.

    It's genius. A great product for the vast majority, while leaving more expensive products as the best option for that elite that will actually spend $600 to $1000 for a processor.

    Well done, Intel. It's not like AMD has anything to say about it.
    Reply
  • Without the baseline clock for clock comparison (4.5 sandy vs 4.5 ivy), i'm afraid these results are pretty much useless. It's like doing an uncontrolled experiment and passing it off as real science.
    Reply
  • digiex
    as the manufacturing process gets smaller = Smaller die size, supposed to be cooler temperature,

    but, with small die size = small area for heat dissipation,

    ...an irony that needs to be solved.
    Reply
  • slicedtoad
    Recommending a closed loop liquid cooler? really?

    They perform worse than decent air coolers. The lower end ones (think corsair's h60) perform like mid-low range air coolers and cost more. The better ones (h100 or antec's 920) perform on par or worse and with more noise than a similarly priced noctua. If noctuas looks too ugly for you, phantek and several others offer similar performing models.

    The only reason to get closed loop lc is for looks. I admit they do give your build a nice clean look. That doesn't warrant "So, we're recommending a closed-loop liquid cooling setup, at least" though. If you'd changed that to "We're recommending higher end aftermarket coolers for a decent oc", it would've made more sense.

    Anyway, I'm just nit-picking a single line from the article. All in all, it was a good read. It just makes me upset to hear wrong advice.
    Reply
  • _Pez_
    there is no performance advantage over the i7 2600k except for power consumption. I better buy an i7-3930k.
    Reply
  • mesab66
    Absolutely true, digiex.......not far off the animal world parallel - check out the different temperature regulation methods here between large and small animals, particularly how difficult it is to regulate as the size becomes smaller.
    Reply
  • I would like claims that Ivy Bridge procesor is overheating considerably more then Sandy Bridge addressed. And I thin k Intel really should make a better overall product and not cheat us like this.
    Reply