Much Ado about L2

When Apple announced its Penryn upgrade clock speeds went up but in some cases L2 cache sizes went down. If you exclusively follow Apple hardware releases then changes in L2 cache size may be difficult to quantify in terms of performance impact, luckily we tend to be a little obsessed with CPUs at AnandTech so we can help clarify and, later, quantify.

Clock-for-clock, Penryn is between 0 - 10% faster than Merom across a variety of applications. On average Penryn is closer to 2 - 3% faster than Merom, at the same clock speed and that’s with a larger L2 cache. With the Penryn update, Apple bumped the clock speeds of all of its notebooks but in some cases reduced L2 cache size.

Intel offers two mobile Penryn cores: one with a 3MB L2 and one with a 6MB L2. Today’s applications, at least on the PC side, tend to fit very well within Merom’s 4MB L2 cache so you shouldn’t expect a significant performance increase, if any at all, from the larger L2 cache.

Back when Intel offered Core 2 CPUs with a 2MB L2 cache, we generally saw an 4 - 10% difference between them and the 4MB parts, averaging closer to 4%. Assuming performance scales linearly with cache size, the 3MB L2 chips should be marginally slower than the 4MB counterparts they replace. However, Apple didn’t just reduce L2 cache size, it also increased CPU clock speed at the same time. At the low end of the spectrum with the MacBook, the base configuration went from 2.0GHz to 2.1GHz, an increase of 5%. The 2.2GHz MacBook is now a 2.4GHz MacBook, an increase of 9%.

The MacBook Pro's base configuration also went from 2.2GHz to 2.4GHz (9% increase in CPU speed). By and large the increase in CPU clock speed should be able to erase any loss in performance from the smaller L2 cache, so we’d expect that at the same price point, the new MacBook and MacBook Pro CPUs won’t be any faster, but not any slower either.

Keyboard Updates

With the MacBook Air Apple introduced a revised keyboard with different function key mappings across the top. Historically, F9, F10 and F11 have been the Exposé keys; F9 Exposé-d across all windows, F10 did it to all windows in a single application and F11 moved all windows away revealing your desktop. OS X 10.4, Tiger, introduced the Dashboard, a great innovation that helped reduce window clutter by allowing for a separate desktop overlay with useful widgets. Apple mapped Dashboard to the F12 key.

The problem with using function keys on a notebook is that they are generally double-mapped. Hold down the fn key and they perform one task, otherwise they perform another.

It used to be that if you wanted access to the brightness, backlight and audio control buttons on the keyboard you had to disable the function-lock. Unfortunately if you did this, then you had to hold down the fn key whenever you wanted to access Exposé or the Dashboard. F3 and F4 are now dedicated Exposé and Dashboard keys, the point being that you can get the best of both worlds.


F3 is the Exposé key and F4 is the Dashboard key


Same on the MacBook Pro keyboard

Without fn-lock enabled, you can now use all of the keyboard hotkeys while also being able to Exposé all windows and view your Dashboard. Unfortunately the world isn’t perfect and I still like to be able to Exposé only a single application’s windows or just reveal my desktop, both of which still require the use of the fn-key (or enabling fn-lock). Unfortunately Apple has run out of fn keys at the top of the keyboard so it’s impossible to add these two additional Exposé functions without reducing functionality elsewhere.

I’m not sure what the solution to my problem is, but that’s for Apple to figure out, at best I can just complain about it.

What’s New? Oh Hashmir, Multitouch Me Down There
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  • steveyballmer - Tuesday, July 08, 2008 - link

    ... being a mac!

    get real people! Vista is the thing!

    http://fakesteveballmer.blogspot.com">http://fakesteveballmer.blogspot.com
    Reply
  • alisonkay2008 - Friday, March 07, 2008 - link

    You can get the best Macbook Pro Case at Macbook Pro Case Reply
  • alisonkay2008 - Friday, March 07, 2008 - link

    Sorry... the link didn't work.
    http://www.macbook-pro-case.com">http://www.macbook-pro-case.com
    Reply
  • JAS - Tuesday, March 04, 2008 - link

    FWIW, MacWorld Labs is reporting that the new "entry level" MacBook Pro is about 10% faster than the model it replaces.

    http://www.macworld.com/article/132330/2008/03/mac...">http://www.macworld.com/article/132330/2008/03/mac...

    On this third year anniversary of my current laptop, I'm headed over to the Apple Store to purchase the 2.4 gHz model. Thanks to Anand for providing his helpful analysis.
    Reply
  • brunerd - Tuesday, March 04, 2008 - link

    Quick note about the Exposé key and some modifier keys:
    If you hold down Command when pressing Exposé (F3) it shows Desktop
    If you hold down Control when pressing it, it shows just the App Windows

    So you don't have to resort to fn-f12 or fn-f11 to get the above behavior.

    Thanks for the write up, nice to know it's running cooler.
    Reply
  • louieking - Tuesday, March 04, 2008 - link

    I was very disappointed that you did not compare the new Penryn 2.6GHz, 200GB- 7200RPM model with the 2007 Merom 2.6GHz, 200GB- 7200RPM model. I don’t think the tests were comparing apples for apples. I think most people interested in your reviews would have wanted to see the difference in overall performance (processing times, battery life) as it relates to lower voltage demands of the Penryn. This would have shown true comparison in battery performance since I suspect that the Penryn version would out-perform in all tests and still have better battery life by a few minutes. Lastly, I think many folks would have been intrigued with a test that showed Firewire 800 download speeds as it relates to battery life. This is an everyday task that would make a difference for a professional MacBook Pro user.

    PS. It’s not too late to WOW the world with your review since you usually beat everyone else to the punch.

    Thanks for your insight.
    Reply
  • azca - Monday, March 03, 2008 - link

    Hint: you can use a tiny driver/software to control the frequency of the intel cpus to show better comparison in your charts:

    http://www.coolbook.se/CoolBook.html">http://www.coolbook.se/CoolBook.html

    Please, if you can, use this for your next review so that you can have better apple-to-apple comparison.

    You can also use the program to undervolt the cpu and hence measure the thermal output and lifespan of battery etc.

    Thank you.
    Reply
  • Pete248 - Monday, March 03, 2008 - link

    While the MacBook Pro keyboard isn't bad, I'm really wandering, why Apple didn't switch to the new keyboard they now use in the MacBook, the Air and the external keyboards.
    Having tried both side by side, the new keyboard feels more definite than the MacPro keyboard. And its probably less susceptible to dust, crumbs and water - the later killing the MacBook Pro keyboard easily - even in traces.
    With a new keyboard I would have pulled the trigger for a purchase, now I'm holding back to see what comes within the next 3 months.

    Reply
  • Wolfpup - Monday, March 03, 2008 - link

    The review says Intel's upcoming video would help the Macbook Pro with Blu Ray playback. Presumably that should have said help the Macbook, as the Pro doesn't use integrated video, and has already had a GPU that accelerates Blu Ray playback for most of a year.

    [quote]MelCarnahan, 2 hours ago
    The author claims Apple picked the right CPU partner in Intel, yet these Intel CPUs could not come close to matching a 32nm Quad Core IBM Cell processor with 2000 MHz FSB. It is disingenuous to compare these Intel egg fryers with a single core PowerPC with a 133MHz FSB. Clearly the Cell processor is superior both in performance and battery life. Only those who wish to use their Yonahs to fry eggs prefer Intel. [/quote]

    Is this some kind of joke? If so, I don't get it. There's so much wrong with this post I don't know where to start, and someone else can do a far better job explaining why, but off the top of my head:

    Cell is a TERRIBLE general purpose CPU. It gets destroyed by Netburst architecture, let alone Intel's modern CPUs. It's great for specific things, but would be terrible for a computer (and is very questionable for a game system for that matter...)

    As far as I know, Intel is a who process ahead of anything Cell is produced on. Geez, the PS3 version is only now hitting 65nm.

    I have no idea why Cell would run COOLER. If anything I'd assume the reverse is true, and certainlly it is anyway because AFAIK there's no 45nm Cell (let alone 32nm as claimed).

    [quote]The Yonah fans sound distinctly like one of those unarmored Humvees with its muffler blown off. The Merom 2.2 Macbook Pro is an improvement but still far hotter, louder and short-batteried compared to the PowerPC. [/quote]

    The Macbook Pro's I've used are dead silent unless they're pushed-but that's a case design issue. I have no idea how they compare to the G4 that was used in terms of the power they use, but I don't think it was much different, and certainly Intel's CPUs would destroy those G4s in terms of power/performance.
    Reply
  • MelCarnahan - Monday, March 03, 2008 - link

    The author claims Apple picked the right CPU partner in Intel, yet these Intel CPUs could not come close to matching a 32nm Quad Core IBM Cell processor with 2000 MHz FSB. It is disingenuous to compare these Intel egg fryers with a single core PowerPC with a 133MHz FSB. Clearly the Cell processor is superior both in performance and battery life. Only those who wish to use their Yonahs to fry eggs prefer Intel.

    Secondly, Macbook and Macbook Pro keyboards are a disaster. Forget bells and whistles and multitouch. They don't even get the basics right. These are basically what was long derided as cheap chiclet keyboards for many years. The backlighting is frivolous when you consider that even at the dimmest setting, the screen is enough to light up a room. The screen is certainly bright enough to light up both the room and the keyboard. The first and most important requirement of any keyboard is a dedicated, full-size page up and page down key. Second, full-size arrow keys. Even the first TRS-80s got this right and Apple still can't get it right. They could create a feature where you waddle your elbows like a duck while holding up three fingers and bending your knees and then the page scrolls down a page - or they could just include a proper page-up and page-down key.

    The Yonah fans sound distinctly like one of those unarmored Humvees with its muffler blown off. The Merom 2.2 Macbook Pro is an improvement but still far hotter, louder and short-batteried compared to the PowerPC.

    For solutions see: http://www.terrasoftsolutions.com">http://www.terrasoftsolutions.com

    Reply

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