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FX Vs. Core i7: Exploring CPU Bottlenecks And AMD CrossFire

Power And Efficiency

Today is AMD’s big chance to prove the value of its FX-8350 in a gaming environment, particularly with a price tag far lower than the competition from Intel. You see, it might appear that Intel has an advantage in our test because we picked its highest-end Ivy Bridge-based chip (the same opportunity given to AMD, by the way). But the price difference between the two doesn't escape us. Intel will need to justify its higher price in relation to the FX-8350.

But first, a look at power consumption and efficiency.

The FX-8350's stock power consumption doesn't look too terrible compared to Intel's, even though it's indeed higher. But we don't get the whole story from this chart, either. We didn't see AMD's chip running at its rated 4 GHz when it was under duress at stock settings. Rather, it dropped both its multiplier and voltage level under an eight-thread Prime95 workload to stay within its rated power envelope. Throttling artificially curbs the CPU's power consumption, and the big increases we see when the Vishera-based processor is overclocked come from fixed multiplier and voltage settings.

At the same time, games don't really utilize the FX-8350's ability to handle eight threads concurrently, and consequently never seem to trigger the same throttling mechanism. Also interesting is that the FX-8350, at its stock voltage setting, often exceeds the 1.35 V we set manually for overclocking. That explains why system power consumption doesn't change much between the stock and overclocked GPU load tests.

As mentioned, the stock FX-8350 doesn't throttle at all during gaming, since most titles aren't able to fully tax the chip. In fact, games actually enjoy a benefit from Turbo Core technology, which takes the CPU to 4.2 GHz. AMD’s biggest problem in the performance chart, then, is that Intel walks away with a noticeably higher average.

Using the average power consumption and average performance of all four configurations as the average for our efficiency chart, AMD's FX-8350 generates around two-thirds as much performance per watt compared to Intel's Core i7-3770K. If you’d like to run these calculations yourself, please note that we zeroed-out the average by subtracting one (100%) from the charted values.

  • A Bad Day
    We were hoping that AMD's Piledriver update would break that trend, but even a handful of impressive advancements aren't enough to match the effectiveness of AMD's graphics team. Might Steamroller be the evolutionary step forward needed to unleash the GCN architecture's peak performance?

    I disagree. What's needed is even stronger push on the developers to use more than four cores, effectively, not some 100% load on one core and 10% on the other five cores.
    Reply
  • acktionhank
    Great article and very informative. The FX-8350 really held it's own until it came down to Skyrim.

    A Bad DayI disagree. What's needed is even stronger push on the developers to use more than four cores, effectively, not some 100% load on one core and 10% on the other five cores.
    I thought more cores were for multi-tasking, as in having multiple programs running simultaneously. It would suck to turn on BF3 and everything else running on my PC simply shut down because the CPU is under 100% utilization. How would i be able to play BF3 while streaming/playing some HD content on my TV that's hooked up to my same computer.


    Reply
  • alidan
    acktionhankGreat article and very informative. The FX-8350 really held it's own until it came down to Skyrim.I thought more cores were for multi-tasking, as in having multiple programs running simultaneously. It would suck to turn on BF3 and everything else running on my PC simply shut down because the CPU is under 100% utilization. How would i be able to play BF3 while streaming/playing some HD content on my TV that's hooked up to my same computer.
    single core performance... look up some other benchmarks, where they use itunes to encode things, or when i believe winzip went from single core to multicore, it shows a GREAT difference more cores can do to performance.

    the problem is that few games and few programs really scale, sure, pro applications almost always take advantage of whatever you put in them, but consumer, different story.

    more cores can offer more multitasking, but they also allow the load to be shifted from one core to all 4 cores and get over all more performance when properly coded.
    Reply
  • Someone Somewhere
    Personally I'd like to see the i5-3570K included in here. It's closer in price to the 8350, but should perform more like the 3770K (as the games are unlikely to use more than 4 threads).
    Reply
  • Crashman
    A Bad DayI disagree. What's needed is even stronger push on the developers to use more than four cores, effectively, not some 100% load on one core and 10% on the other five cores.I'm calling BS on this one because AMD's "eight cores" are actually four modules, on four front ends, with four FP units. Games have historically been limited by FP units specifically and front ends in general, no? What I'm seeing is that Intel's per-core IPC appears to be a little higher, when two different FOUR "full" CORE processors are compared.
    Reply
  • esrever
    There should be an i5 included just so you can have a middle ground.
    Reply
  • amuffin
    I'm really liking the new logo!
    Reply
  • de5_Roy
    like the article.
    woulda liked to see how a 3570k does against the fx8350 running the same cfx setup. impo, the price/perf woulda tipped further in favor of intel in configs like this.
    lastly, woulda liked some newer games like sleeping dogs, far cry3, max payne 3 in the benches instead of the ol' bf3 single player. i hear bf3 sp doesn't stress cpus that much. may be bf3 skewed the benches in favor of amd as much as skyrim favored intel. :whistle:
    Reply
  • quark004
    all these benchmarks are manipulated. First, there is this site which claims the 7900 series does well even with mid level cpus in gaming scenarios. And now toms claim a high end cpu. There is some propoganda here.
    Reply
  • abbadon_34
    It would be nice to see prices for components similar the SMB. Not because I can't look them up, but because the article is very price/performance oriented
    Reply