What does the GHz of Macbook Pro Processors really mean?

Discussion in 'PowerPC Macs' started by greelsvish, Dec 9, 2011.

  1. greelsvish macrumors newbie

    Joined:
    Dec 9, 2011
    #1
    I was just browsing the Apple website, as they have recently update the specs of their Macbook Pro's. I've been teaching myself a lot of Computer hardware specs recently and I'm just getting to know what they all mean (I want to build my own computer some day).

    Anyway, here's the line-up:

    13-inch: 2.4 GHz
    2.4GHz dual-core
    Intel Core i5
    4GB 1333MHz
    500GB 5400-rpm
    Intel HD Graphics 3000
    Built-in battery (7 hours)
    $1399

    13-inch: 2.8 GHz
    2.8GHz dual-core
    Intel Core i7
    4GB 1333MHz
    750GB 5400-rpm
    Intel HD Graphics 3000
    Built-in battery (7 hours)
    $1698

    15-inch: 2.2 GHz
    2.2GHz quad-core
    Intel Core i7
    4GB 1333MHz
    500GB 5400-rpm
    Intel HD Graphics 3000
    AMD Radeon HD 6750M with 512MB GDDR5
    Built-in battery (7 hours)
    $2099

    15-inch: 2.4 GHz
    2.4GHz quad-core
    Intel Core i7
    4GB 1333MHz
    750GB 5400-rpm
    Intel HD Graphics 3000
    AMD Radeon HD 6770M with 1GB GDDR5
    Built-in battery (7 hours)
    $2499

    17-inch: 2.4 GHz
    2.4GHz quad-core
    Intel Core i7
    4GB 1333MHz
    750GB 5400-rpm
    Intel HD Graphics 3000
    AMD Radeon HD 6770M with 1GB GDDR5
    Built-in battery (7 hours)
    $2899

    From what I thought I knew, the 2.8GHz 13" would be the fastest computer. I thought that the more GHz a processor has, the faster the computer is. Am I right? Surely this isn't true because otherwise all the higher range Macbook Pro's would have equal if not better processors. Please explain what makes a processor worth more, and why these laptops are priced as they are.

    Any help would be much appreciated.
     
  2. dukebound85 macrumors P6

    dukebound85

    Joined:
    Jul 17, 2005
    Location:
    5045 feet above sea level
    #2
    depends what you are doing. For single core apps, the higher clockspeed on the same architecture is faster. If you have programs that utilize more cores, then more core machines are faster (quad vs dual)
     
  3. Goftrey, Dec 9, 2011
    Last edited: Dec 9, 2011

    Goftrey macrumors 68000

    Goftrey

    Joined:
    May 20, 2011
    Location:
    Wales, UK
    #3
    Well to start off, there is 1000mhz = 1ghz

    Then it comes to processors, the 2.2ghz QUAD core will be faster than the 2.8ghz DUAL core at more CPU power intensive apps, but you wouldn't find much of a difference doing web browsing or word documenting.

    Having more processors give the Mac more space to spread the processes out between so having 4 processors instead of 2 for example, even if the (2) has a higher clock, the likely hood is that the (4) would be a lot faster. It's pretty hard to explain without going into more 'techy' language, I hope you know I'm coming from, once you get the hang of it though you'll easily be able to base you idea on what the quicker Mac would be by balancing clock speed and the number of processors.

    EDIT : Basically, having more processors gives the Mac (Or PC to that matter) more of a work surface to spread all of the apps/games etc. out on, making it a lot smoother, and a lot faster.
     
  4. chrismacguy macrumors 68000

    Joined:
    Feb 13, 2009
    Location:
    United Kingdom
    #4
    Ugh. Not quite. How it really works is as follows:
    A Dual-Core CPU in effect has 2 "pipes" where the computer can do things. The clock speed is the rate each of the pipes operates at. Most programs used to only use 1 pipe at a time, so the benefits of multiple pipes didn't occur unless you we're doing lots of things at once (as more pipes means your Mac could do lots of things at once). These days a lot of programs are able to use 2 or 4 pipes simultaneously to get stuff done faster. So a Quad-Core at a slightly lower clock speed is much better for running modern applications as it lets you use 4 pipes at a time (even Mac OS X is optimised to use more than a single pipe at a time, so even the Finder is faster), instead of just the 2 in the Dual Core system. Hence a 2.2Ghz Quad Core is faster than a 2.8Ghz Dual Core for most things these days.
     
  5. Goftrey macrumors 68000

    Goftrey

    Joined:
    May 20, 2011
    Location:
    Wales, UK
    #5
    Isn't that what I basically said too? Without the pipes bit? :p
     
  6. thekev macrumors 604

    thekev

    Joined:
    Aug 5, 2010
    #6
    Given the use of turboboost by Intel, clock rates aren't even really fixed numbers anymore. The cpus are described by their base clock rates.
     
  7. zen.state macrumors 68020

    zen.state

    Joined:
    Mar 13, 2005
  8. adcx64 macrumors 65816

    adcx64

    Joined:
    Nov 17, 2008
    Location:
    Philadelphia
    #8
    Correct, a 2.8 ghz processor can be clocked to 3.2 on the fly by the system.
     
  9. Goftrey macrumors 68000

    Goftrey

    Joined:
    May 20, 2011
    Location:
    Wales, UK
    #9
    I was thinking the exact same thing... Move the thread to the 'notebooks' sections dude :)
     
  10. chrismacguy macrumors 68000

    Joined:
    Feb 13, 2009
    Location:
    United Kingdom
    #10
    Kind've, but you were a bit vague. The pipes analogy is very close to the truth (CPU Pipeline), and a bit less wishy washy than calling it space, given the Mac doesn't actually "spread" stuff out per-se, it just executes 4 things at once. Spreading doesn't really describe parallelisation.

    And to zen: Nope, but I figured its relevant given we get asked this about Dual/Quad PowerMacs regularly.
     
  11. thekev macrumors 604

    thekev

    Joined:
    Aug 5, 2010
    #11
    For the OP, in case you're computer shopping, my suggestion would be for maximum speed, go for any of the quad core machines from 2011. I've seen a few in the Apple store in the $1300-1500 range, especially early 2011 machines which are still Sandy Bridge versions.
     
  12. bishvabis, Dec 10, 2011
    Last edited: Dec 12, 2011

    bishvabis macrumors newbie

    Joined:
    Nov 19, 2011
    #12
    It is true, more Ghz more speed, but not necessarily more power, heres why

    it doesnt tell you how many cores it has
    it doesnt tell you about other features such as Turbo Boost(variable speed CPU)
    which roughly translates to...the processor will increase its speed
    to cope with more processes. This in reverse means that the CPU by
    default is choosing a LOW speed until it cant cope too well so it then
    Boosts its speed higher to cope better.

    You can usually FORCE BOOSTED state from within the BIOS.

    finally then a slight warning.

    the current design philosophy is, we have reached our maximum speeds
    so how can we improve our CPU's, well lets add extra Cores and lets make
    our chipsets SAVE BATTERY which will EXTEND BATTERY life.

    so they are making PC's more powerful not really using speed but
    using DESIGNed in features of multiple cores.
    ____________________
    dell laptops deals
     

Share This Page