Cache, Memory Controller & Overclocking Changes

Despite the title of this section, to my knowledge there haven't been any changes to Ivy Bridge's cache. The last level cache (L3) is still shared via a ring bus between all cores, the GPU and the system agent. Quad-core Ivy Bridge CPUs will support up to 8MB of L3 cache, and the private L1/L2s haven't increased from their sizes in Sandy Bridge (32+32K/256K).

The memory controller also remains relatively unchanged, aside from some additional flexibility. Mobile IVB supports DDR3L in addition to DDR3, enabling 1.35V memory instead of the standard 1.5V DDR3. This is particularly useful in notebooks that have on-board DDR3 on the underside of the notebook; OEMs can use DDR3L and keep your lap a bit cooler.

From Nehalem to Sandy Bridge, Intel introduced fairly healthy amounts of power gating throughout the processor. With little more to address in Ivy Bridge, Intel power gated one of the last available portions of the die: the DDR3 interface. If there's no external memory activity, the DDR3 interface can now be turned off completely. External IOs leak current like any other transistor so this change makes sense. Power gating simply increases die size but at 22nm Intel should have some extra area to spend on things like this.

Memory overclocking also gets a bump in Ivy Bridge. The max supported DDR3 frequency in SNB was 2133MHz, Ivy Bridge moves this up to 2800MHz. You can now also increase memory frequency in 200MHz increments.

Core Architecture Changes Power Efficiency Improvements & Configurable TDP
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  • piroroadkill - Saturday, September 17, 2011 - link

    I'd have liked a little more on this.. What's the source?
    I searched anyway, and found it is using thermal sampling. Presumably it's also seeded. Anyway, I thought it was of interest.
  • Jamahl - Saturday, September 17, 2011 - link

    Don't you get tired of saying "intel is finally taking gpu performance seriously" every year? I do.
  • JonnyDough - Monday, September 19, 2011 - link

    I'd just like to say...

    =) Yes sir, I do.
  • imaheadcase - Saturday, September 17, 2011 - link

    I heard when sandy bridge came out they was considering a GPUless version for enthusiasts who don't need that something they will do eventually?

    I suspect its tied to the core, so not going to happen because of high costs. But wouldn't that save even more power/heat problems with that removed?

    It just seems like its a mobile orientated cpu vs consumer. :D
  • DanNeely - Saturday, September 17, 2011 - link

    With power gating if you're not using the IGP it doesn't consume any power; so the only thing they'd save on is die area by removing it.
  • imaheadcase - Saturday, September 17, 2011 - link

    Ah did not know that part. thanks.
  • fic2 - Monday, September 19, 2011 - link

    "I heard when sandy bridge came out they was considering a GPUless version for enthusiasts who don't need it..."

    Interesting since Intel did the exact opposite - put the only GPU with half decent performance into the enthusiast 'K' series.
  • JonnyDough - Monday, September 19, 2011 - link

    The only people who would actually consider that are businesses and home users who don't play "real" games. :P
  • jjj - Saturday, September 17, 2011 - link

    "I believe that x86 CPU performance is what sells CPUs today"

    That's not all that true anymore,there was a time when apps used by everybody required a fast CPU but that's not the case anymore nowdays..Just a few years ago playing HD content was a chalange on older systems but now ,if you look at usage paterns and what kind of perf is needed, the picture has changed. This is one of the reasons PC sales are not doing so great,there is no need to upgrade your system every 1-2 years.Even Windows is not driving system requirements up anymore.
    In the consumer space GPU and battery life matter more now. Intel is trying to fight all this with lower power consumption, ultrabooks but that far from enough.If they want to survive the ARM "tsunami" (think about the financial part too here not just perf) , they got to push the software to be more demanding too and maybe the easiest is to do it on the GPU side -not in games.
  • MadMan007 - Saturday, September 17, 2011 - link

    Intel's quarterly results say there is less to worry about than hyperbolic ARM domination headlines would lead one to think. One IDF slide showed large growth in emerging markets where the analysts aren't as able to get reliable data. Yes, PC upgrade cycles are longer, but that doesn't mean there is not net worldwide growth.

    There is room for growth in both areas, it's not a zero-sum game, and some things like mobile video consumption actually go hand-in-hand with faster beefy CPUs.

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