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
POST A COMMENT

97 Comments

View All Comments

  • JonnyDough - Monday, September 19, 2011 - link

    4-5 year old GPU? Heh, bud...most hardware takes years to develop. And the HD3000 series may be a bit dated but it makes even the XBox 360 look weak in comparison. Hardly dismal. Reply
  • moozoo - Saturday, September 17, 2011 - link

    Does its GPU support double precision under OpenCL? i.e. cl_khr_fp64
    Does Trinity?
    Reply
  • Ryan Smith - Saturday, September 17, 2011 - link

    We don't have solid details on either one, but don't count on it. The reasons we don't see full FP64 support on non-halo GPUs are still in play for CPUs. Reply
  • Galcobar - Saturday, September 17, 2011 - link

    Perhaps I'm missing something in the acronyms, but the table and text seems to disagree on the availability of SSD caching.

    The text states "All of the 7-series consumer chipsets will support Intel's Rapid Storage Technology (RST, aka SSD caching)."

    The table, however, puts No under the Z75 column for Intel SRT (SSD caching).

    As I understand things, you need RST (software) to support SRT (bound to the motherboard), but without SRT you don't get SSD caching.
    Reply
  • Anand Lal Shimpi - Saturday, September 17, 2011 - link

    Fixed :) SRT is only on the Z77/H77, not the Z75.

    Take care,
    Anand
    Reply
  • mlkmade - Saturday, September 17, 2011 - link

    I know its really early to be talking about this cause ivy won't be out for awhile..but what about what amounts to be "ivyb-e" ? I'm sure details are very scarce...but will it follow the desktop path (both s1155) and be socket compatible? in this case s2011? if ivyb-e is socket compatible with sb-e...that'd be great..but by then all the chipset problems would be fleshed out huh..buy a new mono anyway Reply
  • Anand Lal Shimpi - Saturday, September 17, 2011 - link

    I would hope so, but as of now there is no IVB-E on the roadmaps so anything I'd say here would be uninformed and speculative at this point :-/

    Take care,
    Anand
    Reply
  • ltcommanderdata - Saturday, September 17, 2011 - link

    Does Ivy Bridge finally allow the IGP and QuickSync engine to be available even with a discrete GPU plugged in for both mobile and desktop without resorting to specific chipsets (ie. limited to the high-end chipset) or third-party software (relying on motherboard makers and OEMs to deal with Lucid)? WIth the IGP being OpenCL and DirectCompute capable, even if you have the latest Quad SLI/Crossfire setup it would be useful to have the IGP help out in GPGPU tasks.

    And it's interesting that with AMD introducing a beefier form of SMT with two full integer cores, Intel decided not to similarly increase hardware resource duplication to expand Hyperthreading. Instead Intel is focusing on improving single threaded performance by making sure a single thread can use all the resources if Hyperthreading is not needed. Seeing most software isn't making use of 8 simultaneous threads, focusing on making 4 threads (1 per core) work as fast as possible does make sense.
    Reply
  • Meegulthwarp - Saturday, September 17, 2011 - link

    "As we've already seen, introducing a 35W quad-core part could enable Apple to ship a quad-core IVB in a 13-inch MacBook Pro." Here is to hoping that someone other than apple will also ship a decent 13-inch with a quad.

    Other than that great insight, I really hope the GPU on IVB will be half way useable. I think we've hit a point where CPU performance is more than adequate for 95% of consumers. Now just need to up the GPU performance and get power down so we can use our laptops on battery all day. I'm more than happy with my 2 year old C2D CPU performance but want battery life, hugely tempted with AMD's A6-3400M. But with Bulldozer looming I think I may hold back for 6 months.
    Reply
  • Anand Lal Shimpi - Saturday, September 17, 2011 - link

    I hope so too, I simply used Apple as an example because it has migrated to quad-core in every member of its MBP family with the exception of the 13-inch. I've updated the statement to be a bit more broad :)

    Take care,
    Anand
    Reply

Log in

Don't have an account? Sign up now