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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  • NeBlackCat - Wednesday, September 21, 2011 - link

    The GPU part would be streets ahead, the drivers would be good, Tegra 3 (4..5...) on the 22nm trigate process is an absolutely mouth-watering proposition, and who knows what else could have been accomplished with the engineering effort saved on Intel GPUs and the (so far) fruitless efforts to push x86 into smart consumer devices.

    On the downside, there's be no AMD.
  • mrpatel - Wednesday, September 21, 2011 - link

    The iMac 2011 27" model ships with the Z68 chipset.

    So the question is whether or not it would support IVY BRIDGE CPUs in it? (given that all other things like TDP etc requirements match up).

    I wonder if IVY BRIDGE CPUs would require a full EFI or kernel module upgrade to be supported? (i mean i really don't care if the USB 3.0 works, but I do care about the new design, gpu performance and lower power to performance ratio compared to sandy bridge!).
  • caggregate - Friday, September 23, 2011 - link

    So being that this is a current/future platform, what's the big deal about support for DDR3L (which as a standard was ratified in July 2010)? I realize the specs of DDR3U ("Ultra low voltage" 1.25V) are not "final" yet, but you'd think it would be implemented given that DDR3U has been available to engineers (according to Hynix/Google) since June 2010. Reply
  • fb39ca4 - Sunday, September 25, 2011 - link

    No OpenGL 4 support? Seriously? Reply
  • OCguy - Tuesday, September 27, 2011 - link

    Are they even trying anymore? Reply
  • Olbi - Tuesday, October 18, 2011 - link

    I wonder why Intel add DX11, but no OpenGL 4? Both are needed by developers of apps and DX11 isnt need by allmost all app. OpenGL 4 is needed by Linux desktop like KDE 4, GNOME, Xfce and others. So why Intel still doesnt support it. Reply
  • tkafafi - Tuesday, March 20, 2012 - link

    Why do the new intel chipsets (series 7) still contain so many (10) usb2 ports ? Would any PC/laptop manufacturer chose to use a usb2 port instead of anavailable usb3 port from the chipset ? for e.g would they use 2 usb2 + 2usb3 instead of 4 usb3 from the chipset ?

    I know PC manufacturers are using this configuration (2 usb2 + 2 usb3) because now they need to support usb3 through an external controller so they are saving cost by using a 2 port controller. But once series 7 chipsets arrive with native usb3 support, there would be no cost advantage to do this. Is this to derisk any interoperability issues with older usb2 devices (i.e if for some reason usb3 ports don't work well with some existing usb2 devices) ?


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