AMD Bulldozer Review: FX-8150 Gets Tested

Per-Core Performance

There’s a really good reason why, when we benchmark a processor in a real-world application, the results are often very different from other tests. Explaining why requires breaking down performance in a more understandable way. A processor’s per-core potential is defined by the number of instructions it can execute per cycle and its clock rate.

We can isolate IPC, to a certain extent, by comparing various architectures at the same clock rate using applications designed to run in a single thread. That’s exactly what I did in Intel’s Second-Gen Core CPUs: The Sandy Bridge Review to determine just how much Intel improved the IPC rate of Sandy Bridge.

With its Bulldozer architecture, AMD's architects say it was their goal to “hold the line” on IPC and create hardware that’d scale to much higher frequencies. Given what we already know about the FX-8150's specifications, significantly higher frequencies aren’t being realized today, so before we even run any benchmarks, we have to assume similar IPC throughput, fairly comparable clocks, and then cross our fingers for better scaling across multiple cores if Bulldozer has any hope at all of outperforming the 3.7 GHz Phenom II X4 980 or Turbo Core-equipped Phenom II X6 1100T.

With a Core i7-2600K (Hyper-Threading, SpeedStep, and Turbo Boost all disabled), Phenom II X6 (Cool’n’Quiet and Turbo Core disabled), and FX-8150 (Cool’n’Quiet and Turbo Core disabled) all running our single-threaded iTunes test at an even 3.3 GHz, we see that Intel gets significantly more work done per cycle than the Phenom II X6 1100T, which in turns outperforms the FX. We see the same outcome in Lame, another single-threaded test.

John Fruehe, director of product marketing for server products at AMD, says he doesn’t like the performance per core comparison on the server side because it knowingly favors Intel. I’d absolutely agree that, in the server world, John's view is correct. Performance per watt and performance per dollar are both more pressing metrics in that space. On the desktop, however, enough workloads are still single- and lightly-threaded that per-core performance matters (even more so when the results of that measurement step backward, generationally).

Early on, then, we already have an idea of where the Bulldozer architecture might trip up...

Chris Angelini
Chris Angelini is an Editor Emeritus at Tom's Hardware US. He edits hardware reviews and covers high-profile CPU and GPU launches.
  • btto
    yeah finaly, now i'll read it
    Reply
  • ghnader hsmithot
    nOT Bad AMd!
    Reply
  • jdwii
    Been so long and i'm kinda sad.
    Reply
  • compton
    Not many surprises but I've been waiting for a long, long time for this. I hope this is just the first step to a more competitive AMD.
    Reply
  • ghnader hsmithot
    At least its almost as good as Nehalem.
    Reply
  • gamerk316
    Dissapointing. Predicted it ages ago though. PII X6 is a better value.
    Reply
  • As I expected - failure.
    Reply
  • AbdullahG
    I see the guys from the BD Rumors are here. As many others are, I'm disappointed.
    Reply
  • iam2thecrowe
    for the gaming community this is a FLOP.
    Reply
  • phump
    FX-4100 looks like a good alternative to the 955BE. Same price, higher clock, and lower power profile.
    Reply