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

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By Thomas Soderstrom
published

AMD and Intel continue serving up increasingly faster CPUs. But graphics card performance is accelerating even faster. Is there still such a thing as processor-bound gaming? We take two Radeon HD 7970s, high-end desktop CPUs, and a few games to find out.

Metro 2033, Second By Second

Our Radeon HD 7970s in CrossFire appear to have a little trouble achieving playable frame rates at our highest quality settings in Metro 2033. So, we captured a few images from its benchmark output. At 1920x1080, for example, the FX-8350 is only able to carry these cards to around 30 FPS.

Overclocking the FX-8350 has little effect. The slow spot on the benchmark map simply narrows a bit.

Intel’s Core i7-3770K suffers similarly, though. CPU overclocking yields very little benefit.

Minimum frame rates have to be taken into context. When they occur during the first second or two of a benchmark, as they often do in Metro 2033, we tend not to count them. Instead, we refer to the game's benchmark diagrams to see if performance is actually playable at 4800x900. Unfortunately, even backed by overclocked processors, our CrossFire configuration frequently drops below 20 FPS.

We're not here to evaluate graphics performance, though. Neither Intel's Core i7-3770K nor AMD's FX-8350 makes enough of a difference to make this game playable at the next-highest setting, so the FX-8350's lower price is going to count toward better value.

If you want to look at Metro 2033 in more depth, a full set of result graphs is available in this story's image gallery.

Thomas Soderstrom
Thomas Soderstrom
Thomas Soderstrom is a Senior Staff Editor at Tom's Hardware US. He tests and reviews cases, cooling, memory and motherboards.
164 Comments Comment from the forums
  • 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