This is a very volatile time for Intel. In an ARM-less vacuum, Intel’s Haswell architecture would likely be the most amazing thing to happen to the tech industry in years. In mobile Haswell is slated to bring about the single largest improvement in battery life in Intel history. In graphics, Haswell completely redefines the expectations for processor graphics. There are even some versions that come with an on-package 128MB L4 cache. And on the desktop, Haswell is the epitome of polish and evolution of the Core microprocessor architecture. Everything is better, faster and more efficient.

There’s very little to complain about with Haswell. Sure, the days of insane overclocks without touching voltage knobs are long gone. With any mobile-first, power optimized architecture, any excess frequency at default voltages is viewed as wasted power. So Haswell won’t overclock any better than Ivy Bridge, at least without exotic cooling.

You could also complain that, for a tock, the CPU performance gains aren’t large enough. Intel promised 5 - 15% gains over Ivy Bridge at the same frequencies, and most of my tests agree with that. It’s still forward progress, without substantial increases in power consumption, but it’s not revolutionary. We compare the rest of the industry to Intel’s excellent single threaded performance and generally come away disappointed. The downside to being on the top is that virtually all improvements appear incremental.

The fact of the matter is that the most exciting implementations of Haswell exist outside of the desktop parts. Big gains in battery life, power consumption and even a broadening of the types of form factors the Core family of processors will fit into all apply elsewhere. Over the coming weeks and months we’ll be seeing lots of that, but today, at least in this article, the focus is on the desktop.

Haswell CPU Architecture Recap

Haswell is Intel’s second 22nm microprocessor architecture, a tock in Intel’s nomenclature. I went through a deep dive on Haswell’s Architecture late last year after IDF, but I’ll offer a brief summary here.

At the front end of the pipeline, Haswell improved branch prediction. It’s the execution engine where Intel spent most of its time however. Intel significantly increased the sizes of buffers and datastructures within the CPU core. The out-of-order window grew, to feed an even more parallel set of execution resources.

Intel added two new execution ports (8 vs 6), a first since the introduction of the Core microarchitecture back in 2006.

On the ISA side, Intel added support for AVX2, which includes an FMA operation that considerably increases FP throughput of the machine. With a doubling of peak FP throughput, Intel doubled L1 cache bandwidth to feed the beast. Intel also added support for transactional memory instructions (TSX) on some Haswell SKUs.

The L3 cache is now back on its own power/frequency plane, although most of the time it seems to run in lockstep with the CPU cores. There appears to be a 2 - 3 cycle access penalty as a result of decoupling the L3 cache.

Power Improvements
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  • gregounech - Saturday, June 01, 2013 - link

    Finally, let's see how good Haswell is. Reply
  • Krysto - Saturday, June 01, 2013 - link

    Disappointing, to say the least. He's even comparing it to 2-3 older generations, just to be able to write some non-embarrassing numbers in the review, considering Haswell is only like 5-10% faster than IVB.

    The only big improvement seems to be in idle power consumption, of about 30%, which seems to "impress" Anand, but it just means that if your laptop had a 12h idle time, now it gets 16h.

    It won't do much in ACTIVE power, which is really what matters. So much for all the "Haswell will totally dominate tablets in the near future" hype from Anand. Yes, this is not the mobile version, if Haswell really were an impressive design for power consumption, you'd see it here, too. It actually consumes 5-10% more than same clock speed IVB chip, which means its extra performance is almost completely negated.

    This means that my predictions that Intel will try to "trick" us into thinking Haswell is ready for tablets will soon come true. Because if Haswell is not that efficient to warrant being used in "normal" tablets, then they'll try to dramatically lower clock speed and performance to even achieve 10W TDP (still too high for a tablet).
    Reply
  • gregounech - Saturday, June 01, 2013 - link

    Pretty good points.

    I'll still upgrade from my i5 750, and we won't get anything interesting until Skylake on the desktop (apparently, it wont be BGA), as I'm expecting motherboard OEMs to force us into buying their high end motherboards with any of the high end i7s Broadwell.
    Reply
  • Samus - Sunday, June 02, 2013 - link

    I'm using an i7-950 (over 4 years old) and its funny seeing how still-competitive it is to Intel's newest chips. It seems Sandy Bridge brought the bang and its just been trickle down performance since... Reply
  • Deelron - Sunday, June 02, 2013 - link

    No kidding, I'm in the same boat and was thinking of upgrading but with my moderate over clock and these results have no problem waiting until the next generation. Reply
  • klmccaughey - Monday, June 03, 2013 - link

    I'm still running my i5-2500k @ 4.3GHz and see nothing here of interest. I don't see myself upgrading any time soon. Reply
  • Hrel - Monday, June 03, 2013 - link

    I'm still running an E8400. I see plenty of reason to upgrade. Reply
  • dananski - Monday, June 03, 2013 - link

    Ahh I had one of those until this time last year. The E8400 found a happy home with a friend and I went to Ivy Bridge. Even small improvements like Sandy -> Ivy -> Haswell are useful, so don't feel too bad for having waited so long. Reply
  • vol7ron - Tuesday, June 04, 2013 - link

    haha. I'm still running an OC'd E6600 (amongst others) for my desktop, which I hardly touch anymore, and am unsure whether to upgrade. I'm curious to see how Haswell performance vs power consumption vs price, is for NAS systems.

    Aside from natural degradation in one of the components (cpu, memory, psu, or gpu), which brings on an error every once in a while, the E6600 still does 98% of what I want of it and 100% of what I need it to do. So I suppose my needs are to get my electric bill down.

    I need to read more because I was hoping this chip would bring me to buy a Surface Pro.
    Reply
  • slickr - Wednesday, June 05, 2013 - link

    You will get benefits upgrading from E6600 no doubt about it. For you its worth it as you are going to get a lot less power consumption, cooler operating chip and less noisy as well, with a significant performance increase especially in multithreaded applications, but for those thinking upgrading from Sandy or Ivy bridge to Haswell its worthless.

    I mean upgrading from 2500k to the new 4770k is useless. At best you are going to see 40% performance improvement which calculates into 5 seconds faster decoding or 5 seconds faster unzipping, but at worst you are going to get 2% performance increase which amounts to milliseconds of faster decoding and stuff.

    You are not going to get less power consumption and it seems you may even get worse power consumption at loads. The new chips don't even overclock as well either, so its a waste of money to upgrade. If you have 3-4 generations older chip its worth upgrading, but else your money is better spent elsewhere.
    Reply

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