Apple begins shipping 27-inch Core i7 iMacs

Apple StoreApple has begun notifying customers that their Quad-Core Intel Core i7-powered iMacs have shipped.

Multiple MacDailyNews readers have confirmed the following dates:

Shipment Date: Nov. 11, 2009. Delivers by: Nov. 17, 2009

The Intel Core i5 or i7 processor incorporates four processing cores onto one die, so data doesn’t have to travel far to get from core to core. These “Nehalem” processors include the following features:

• 8MB of shared L3 cache, which boosts performance by keeping data and instructions in a fast-access cache that is available to all four processor cores.
• An integrated memory controller, which allows faster access to data stored in memory by connecting the memory controller directly to the processor, eliminating any middle man and significantly increasing memory bandwidth.
• Turbo Boost, a dynamic performance technology that automatically speeds up the cores in use when other cores aren’t needed.

The Intel Core i7 processor also features Hyper-Threading technology, which allows two threads to run simultaneously on each processor core, providing eight virtual cores for increased performance.

More info about Apple’s powerful new iMacs here.

[Thanks to MacDailyNews Readers too numerous to mention individually for the heads up.]


  1. Could someone please explain the difference between the 2.66GHz Quad-Core Intel Core i5 and the 2.8GHz Quad-Core Intel Core i7 BESIDES clock speed?

    If the two chips differ in some way other than clock speed, under what circumstances would one be likely to see a significant performance boost going to the Core i7?

    Also, what role does “Grand Central” play in all this and when does that technology arrive on our Macs in a meaningful way?

    I’ve always chosen a “PowerMac”-class machine for my personal use and with my aging 2.5GHz PM Quad G5 beginning to look quite faded out in the current Mac OSX landscape, I am wondering if my next machine should be one if these quad core 27″ iMacs…

  2. DataDude:
    Could someone please explain the difference between the 2.66GHz Quad-Core Intel Core i5 and the 2.8GHz Quad-Core Intel Core i7 BESIDES clock speed?

    From an end user point, it will be that the i7 contains hyperthreading across the cores. So in theory you will be seeing ‘8’ CPU’s in activity monitor. Grand Central will be able to use these ‘extra’ cores when it does its magic.

  3. @ Lava_Head
    @ johnsonville

    So what has to happen before average users (or even “Power Users”) begin to see real performance gains from “hyper-threading”?

    And when will we begin seeing this happen? Will these performance gains eventually trickle down to all Mac apps?

  4. @DataDude
    My understanding is the Snow Leopard already takes advantage of Grand Central Dispatch. Since SL has been out for a few months, I wouldn’t be surprised if you started seeing major software vendors releasing updates to take advantage of Grand Central, as well.

  5. @DataDude

    Hyperthreading isn’t new however it has (and had) its trade offs in the past. Some apps benefited from it, others were hurt from it. The hyperthreading in the i7’s is different from the original implementation so its a good assumption that performance gains from it should be decent.

    As far from end user’s noticing it, Apple’s goal would be that its transparent to the end user ” width=”19″ height=”19″ alt=”grin” style=”border:0;” /> But seriously, the API’s used for Grand Central are baked into Cocoa and to use those, an application would just need to call the normal APIs and GC will do the rest (well, its not that easy technically from a programming point of view, but we’ll keep it that way in this discussion). Currently you can see benefits from most of the built in apps which are Cocoa built and 64-bit:; Quicktime X; etc. As the apps are turned over to true 64-bit and Cocoa frameworks end users will see more and more situations where the CPUs in Activity Monitor begin scaling in unison when heavy CPU calls are made.

    Will an i7 outperform a Mac Pro? Nope. Will an i7 perform well for some moderate graphics work? Surely.

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