Overclocking: Core i7 Vs. Phenom II

This match-up needs no introduction—but I’m going to throw one down anyway.

It’s no secret that Intel has dominated our performance tests over the past year. First, its Core 2 Duos at 45 nm gave enthusiasts a great platform for aggressive, yet relatively safe overclocking. The company’s Core 2 Quads cost quite a bit more, but they managed to deliver smoking speeds in the applications optimized for multi-threaded execution.

The recent Core i7 launch further cemented Intel’s position as the performance champion. Its Core i7 965 Extreme, clocked at 3.2 GHz, demonstrated gains straight across the board versus its outgoing flagship, the Core 2 Extreme QX9770. And the Core i7 920, Intel’s sub-$300 entry-level model running at 2.66 GHz, seems to have little trouble reaching up to 4 GHz on air cooling.

There was once a time when Intel didn’t handle its technology shifts as smoothly. As recently as the Pentium 4 Prescott core (OK, that was a while back), Intel struggled to maintain an advantage against AMD’s Athlon 64. But now, with the marketing of its "tick-tock" approach to rolling out lithography advancements and micro-architecture tweaks, things have certainly turned around. How is AMD expected to compete?

Up until now, AMD has relied on the loosely-translated term "value" to keep in the game. On its own, the Phenom X4-series is a moderate performer. AMD knows this, and has priced the chip more competitively than Intel’s quad-core offerings to attract attention. However, the Phenom hasn’t had to exist alone in an ecosystem backed by third-party vendors. It’s instead complemented by AMD’s own chipsets, mainly the 790GX and 790FX. Of course, those platforms extend comprehensive CrossFire support for its own graphics cards, which have been capturing hearts since mid-2008.

Combined, AMD’s processors, chipsets, and GPUs have fared better than any one of those components would have alone. Thus, we’d consider the company’s efforts to emphasize its Spider platform—the cumulative result of all three puzzle pieces—a success.

AMD Needs Something New

In light of a new competitive challenge—Intel’s Core i7—AMD is revamping its Spider platform with a new processor and the addition of software able to tie all of the hardware together. As you no doubt already know from reading Bert’s story, this latest effort is called Dragon.

But we’re not here to rehash the details of Phenom II. Rather, in light of significant enhancements to the CPU architecture’s overclocking capabilities (and indeed, confirmation from AMD that all of the "magic" that went into its ACC [Advanced Clock Calibration] technology is now baked into Phenom II), we’re eager to compare the value of AMD’s fastest 45 nm chip to Intel’s entry-level Core i7 920—the one most enthusiasts would be likely to eye as an overclocking contender.

In the pages that follow, we’ll describe how each platform was overclocked, just how hot each system got, how much they cost, how well they perform at their top speeds, and, ultimately, which should be on the short list for your next upgrade.

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  • fwibbler
    When the Phenom dropped to 800mhz at idle, was the voltage also lowered or was that still running at 1.6 volts? Same question for the Core i7 too.
  • papalarge123
    wouldnt it have been better for both CPU's to have been run @ 3.6Ghz, as this was the Phenom 2's sweet spot, keepin them equal.

    also, as the I7 can run on Dual channel memory also, u should have run both systems @ dual channel with 4Gb of RAM to keep things equal,

    if these changes were done, i believe that the i7 would have still beat the Phenom 2, but i dont think the gap would have been so high.

    as for the Hyperthreadin, is there any way to turn them off, as i believe that this is what gives the core i 7 the advantage on some of the app tests.

    having these settings and benchmarks are great to see what they are capable of when set to full, but i and others would like to see both chips perform side by side with exact seetings as each other, this will give us a true sight of what the Phenom 2 architecture is capable of doin against an intel chip without the fancy extras.
  • jasoncrussell
    Did seem very strange to use only 4G of RAM for AMD chip and 6G for i7. Would have been nice to see them both using 4G and seeing how close they were then. Reckon i7 would still of been quicker though. AMD needs to hope it's AM3 platform can close the gap, because at this moment Intel are way ahead in the performance stakes.
  • Faldrax
    Why are people worrying that the tests were not 'equal'?
    The point of them (in part) is to show how one has an advantage over the other. The Intel costs more, but you get more for it - the question is how much.
  • Kari
    huh, so you just upped the multi and voltage on the amd system?? I have this weird feeling that there are other settings as well to tweak...
  • LePhuronn
    And until Core i7 has mainstream parts I don't know of a single enthusiast who's running their system anything other than triple channel anyway, so you can't get 4GB on the i7. Giving the Phenom 2x2GB and 2x1GB would take it up to 6GB and still maintain Dual Channel if you really want to match RAM sizes (or run both at 3GB with 2x1GB and 2x512MB on the Phenom).
  • Nyar
    could the shoddy CPU cooler for the AMD system possibly be behind hte really poor overclock????the intel setup get possibly hte best cooler on the market, one that is AM2 compatible i might add so no reason not to use it for both.
  • Anonymous
    Wouldve been better if they used the DFI 790FX/SB750 mobo instead of the Asus, i hear it has problems wit overclocking.
  • papalarge123
    actually u will find that the i7 is capable if running in dual channel.

    i know the i7 is alot better than any thing on the market ATM, but i myself and most other people would like to see a true comparison, where everything is truely equal see who is the tru winner.

    i believe that if these extra settings that Intel have on there chips were to be disabled, then there wont be so much of a difference in the benchmarks.

    some of the biggest differences could be claimed as the i7 was overclocked higher.
    well put them to gether with the same overclock and see them perform head to head in a true clock for clock shoot out.

    other factors could be tributed to the extra thread processin by the hyperthreading of the i7, dissable this to allow for a true quad shoot ot with a gain the same overclock.

    if this was to be done, i also believe that it will close a lot of arguments out there, whether the i7 is etter for the fact that it is a better chip, or wether the extra features are a contribution.

    im not knocking Intels new flag chip, but i believe that if u realy want a true comparison, then show what they are capable of on the same turf, and then allow for the true pedigree of both chips to shine through with what the are capable of on there own turf.

    I personally would like to see this, as the architecture is supposedly the same, lets see what true differences there are in the architecture,
  • x3style
    I would also like to see a true side by side comparison. And i think AMD could have gone higher with a better air cooler.
  • Anonymous
    Really strange conclusion drawn here. Conclusions like:
    "sacrifice a bit of speed" and "handle every task nearly as well as i7 does" are in my opinion, totally WRONG. The i7 crushes almost everything the 940 does, except for maybe one case or two.
    Further on, the real world gaming examples given here are mainly GPU-bound and shows nothing of the potential availible in the i7. Running graphics settings at "very high" does not show differences in CPU speed and thats why results are equal between the CPU.

    Actually you do say that "Intel’s Core i7 920 overclocked to 3.8 GHz simply delivers the most compelling experience".
    Even here you contradict the quotes on top. And I also believe the non-overclocked i7 would deliver the most compelling experience.

    Ive read many reviews on the CPU doing exactly the same errors performed here. For a GOOD review of the CPU I would recommend.


    Comparing games at 640 resolution gives a much better hint of non GPU-bound performance

    /AMD x2 3800+ user
  • papalarge123
    I am sorry that u dont feel that what has been stated is correct or feesable, but to call me an AMD fanboy, is disrispectfull, as i currently own an Intel Q6600.

    i go where the best performance and price comes into factor.

    i just think that if ur going to compare 2 CPU's, show what they are capable of, then show what they are on the same terms, this will truely show what the differences are between the 2 cores which is what has dragged up debate since intel announced the design features of the i7.

    i would just like to see the 2 cores battle it out on a so called even score, where the 2 cores can shine without fancy features.

    but in the long run i know the full features of any CPU or any component is what matters and also will determine the sale.
  • Jetinder
    What this proves is one of intels slowest i7s is still better than AMDs newest and best of the best.

    I heard in 2-3 years time AMD will move from AM2+ and AM3 sockets to a new one (which will need a new cpu and new motherboard), based on that it would be better for current Intel owners to stick with core2 duos and get the i7 as either way they will need to buy a new motherboard etc and i7 is better than AMD.

    In the old days AMD where great i have an old Athlon 2500 XP and 6 years ago that thing beat Intels Pentium versions, Its a pity AMD lost its way with the current set of cpus.
  • avatar_raq
    Core i7 entry CPU beats the best Phenom II !! Intel is definitely the winner. And the price difference is fair from a value point of view. Besides; applications are, and always were, more optimized for intel processors, which I consider an advantage for intel.
    Chris: I think the games' benchmarks should have been run on lower resolutions to shift the bottleneck from the GPU to the CPU to further demonstrate core i7's lead.(Especially in Crysis)
    For those who demand clocking both CPUs @ the same clock and using dual channel memory for both: It's not a comparison of clock to clock performance (though the performance gain of core i7 is larger than the clock difference which means its c2c performance is better), its a comparison of the maximum perf. you can get from the 2 systems putting in mind current prices and upgradibility. And the article has made everything clear. Good job, Chris.
  • avatar_raq
    jasoncrussellDid seem very strange to use only 4G of RAM for AMD chip and 6G for i7. Would have been nice to see them both using 4G and seeing how close they were then.

    Do you honestly think the 6gb ram had a real advantage over the 4gb in performance? Even Crysis doesn't use the extra 2gb!! What's really beneficial here is the triple channel bandwith. How much exactly the 3rd channel is adding to overall performance is still unknown to me and many readers, I believe we need a dual channel vs triple channel benchmarking!
  • Anonymous
    please stop being so lazy and put the prices in £.
  • will_chellam
    I would have thought the comparison was completely fair - take two chips, overclock them as far as they are stable then run some benchmrks, cant get much fairer than that.

    Someone suggested disabling hyperthreading in the i7, a better idea would be to enable it on the phenomII - wait it doesnt have it..... thats like saying my ferraris better than your lambhorghini, so ill run it with 3 wheels just to give you a chance... pointless.
  • will_chellam
    actually, ive just read the setup and the i7 wasnt even clocked as far as it would go! if they kept it at 4ghz (which they did achieve) and ran teh settings again, the difference would surely have been even greater.
  • Anonymous
    I feel like the conclusion was written by someone who is trying to think of ANYTHING he can to give AMD an edge, even though the facts speak for themselves. The intel proc decimates the AMD proc, and the price difference is crap. As for the people who want half the features of the Core i7 turned off to make it equal - are you nuts? What do you think you're paying for when you buy a Core i7? You're not going to turn everything off and run it cripled... you're going to unleash the power of the machine. if you have a problem with price, wait an extra 2 weeks for a paycheck and bump down to 3GB of ram. I'm a huge AMD fan, but AMD is getting rocked. They need to wake up and release something worth buying.
  • geekbox computers
    I'm a huge AMD fan, but AMD is getting rocked. They really need to release something worth buying, but unlike what the author would suggest - this isn't it. The phenom II isn't worth putting in a new rig, not at a 250.00 price dif. You're talking about Old technology, DDR2. Wouldn't it make more sense to drop down to 3GB of ram and eat top roman for a week, instead of buy something that will be gone tomorrow? Like I said, HUGE AMD fan here; and I know many of you AMD fans want to defend it to the bitter end - "Turn off hyper threading, run 4 gb or ram... blah blah blah" - but let's not kid ourselves... Are you really going to run the processor in crippy-mode when you buy one? No way...