Lion is running REALLY slow for me!

Discussion in 'Mac OS X Lion (10.7)' started by nysegop, Jul 19, 2012.

  1. macrumors newbie

    Jun 8, 2012
    Lion is running EXTREMELY slow on my macbook. I recently upgraded from 10.6.8 to 10.7.whatevernewestversionis. Now I cannot perform simple tasks such as navigating in finder without the spin wheel loading for a minute. Forget about using the computer for games or even safari sometimes. I have to force reboot about 6 times per day. This is seriously frustrating. Any help?

    Tech Specs:
    Previous System: 10.6.8
    2010 Macbook (White)
    Intel Core 2 Duo
    2.4 GHz
    2GB 1067 MHz DDR3

    Things I have tried:
    Repair Disk Permissions (Didn't help that much but curiously made rebooting a quicker process)
  2. macrumors newbie

    Jul 20, 2012
    new delhi
    lion working slow

    same with me tried doing everything disk repair deleting software i don't use.

    macbook 2008 late
    2 ghz core 2 duo
    lion 10.7.4

    everything was ok when i was on leapord.
  3. macrumors 68040


    May 8, 2011
    Los Angeles
    my 2007 MBP runs with 10.7.4 is GREAT!! How? Cuz I have 4GB memory and SSD :D
  4. macrumors Westmere


    May 16, 2008
    1. Launch Activity Monitor
    2. Change "My Processes" at the top to "All Processes"
    3. Click on the CPU column heading once or twice, so the arrow points downward (highest values on top).
    4. Click on the System Memory tab at the bottom.
    5. Take a screen shot of the whole Activity Monitor window, then scroll down to see the rest of the list, take another screen shot
    6. Post your screenshots.
  5. macrumors 6502


    Nov 20, 2007
    Why lion is slow

    I think it may be related to llvm:

    On Snow Leopard, the default compiler is GCC 4.2 (WITH NO LLVM)
    On Lion, the default compiler is GCC-LLVM, then later Clang-LLVM (because GCC-LLVM was actually
    half broken).

    So the major changes from Snow Leopard to Lion is the mandatory use of LLVM.
    In the case of LLVM backend producing code running in virtual machine, it has support for
    grabbing chunks of memory to do memory allocation (they need to in order to do automatic
    reference counting and garbage collection). Kernel bloat? Could it be that LLVM, in its support of interpreted language features, carried these baggage, which resulted in bloated and slow code even
    if you are compiling static CLang or GCC code? Remember, LLVM intermediate IR
    (byte code in java) is VERY FAR REMOVED from standard GCC intermediate code. It is more abstract,
    to the point where you can actually run the llvm IR inside a virtual machine (no different than C# or Java).
    So the process from llvm IR to regular .o or regular binary executable is not as cleancut as GCC.

    In addition, LLVM takes about 5 times more main memory than GCC:

    Remember in OpenGL, there were some code left in intermediate state? When that kicks in the llvm
    compiler starts up. We don't know what other parts of the OSX were left in this state that REQUIRES
    compilation at runtime, and JIT compilation (like Java JIT). Perhaps more and more pieces in
    Snow Leopard and cumulating in full blown llvm requirement in Lion. Only in Lion was full
    LLVM required everywhere. This could lead to kernel
    bloat because OpenGL (driver) is near the Kernel level when running when these non-compiled
    code needs to be JIT compiled. It could be other low level pieces. Remember this is 5 TIMES the required memory. So something
    that normally requires 1GB would now require 5GB during runtime. A Mac Mini only has 4GB and
    so are lots of earlier Mac machines. A lot of disk thrashing will occur as more things are moved
    back and forth to the harddrive to accomodate that startup of the llvm virtual machine backend just
    to compile, and if virtual machine is used, the amount of memory never dissipates.

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