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

Features
By Achim Roos, Patrick Schmid
published

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.

More Voltage, More Heat

Our evidence shows that, at similar clock rates, 32 nm Sandy Bridge-based processors don't get as hot as the new 22 nm Ivy Bridge-based chips. As a result, our Core i7-3770K dropped its overclocked frequency sooner in order to protect the CPU's integrity, nullifying the effects of our overclocking efforts entirely. It also discourages setting higher core voltages, since that'd just exacerbate the issue.

Thus, throttling can only be avoided when the target overclock is achieved using the lowest core voltage possible. However, it still has to be high enough to allow the transistors to operate reliably. Old mantras like “a hefty voltage increase helps facilitate a hefty frequency bump” do not work on Ivy Bridge-based chips. Once throttling kicks in, average clock rates drop to around 3.6 GHz. That's a significant reduction compared to the 4.6 GHz we were targeting.

We think that you're going to have the most success overclocking Ivy Bridge if you can stay as close as possible to the CPU's default voltage setting or work really hard to overcome the heat resulting from more aggressive voltage settings. At 4.6 GHz, the voltage increase necessary to get our machine stable quickly resulted in throttling, forcing us to stay at 4.5 GHz. At that speed, we had to increase the core voltage by 70 mV in order for our benchmark suite to run reliably.

As in our launch coverage, 4.5 GHz turned out to be as high as we could go without running into stability issues. It wasn't difficult to get up to 4.7 GHz (or, using one of our samples, even 4.9 GHz). But certain tests consistently cause those frequencies to derail, pushing us back down.

Achim Roos
Achim Roos
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