Windows Boot Times FASTER When Emulated?

Discussion in 'Operating Systems' started by Dario D., Feb 26, 2010.

  1. Dario D.

    Dario D. Gawd

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    Any idea why I can boot Win7 64 and Vista 64 in 15-20 seconds when running them via Virtual Box (on Vista 64)? (VB is a free OS emulation app. You can run your OS's in their own little windows) Vista normally takes me 1:45 (much slower than when it was a fresh install), and Win7 is also up there around a minute, at least (can't remember the exact time). My hard drives are pretty fast (all roughly the same), but, when booting these OS's via Virtual Box, the boot times are suddenly almost instantaneous.

    Is this because Windows normally does a lot of waiting around for hardware, or something, which isn't there when you're emulating?
     
    Last edited: Feb 26, 2010
  2. devil22

    devil22 2[H]4U

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    I doubt it does a lot of waiting, because for instance my Win 7 x64 machine boots in about 20 seconds from a 150GB Raptor. I'm guessing you installed something(s) which slowed down the physical installs that you didn't install in the virtual machines, maybe a bad driver too since the drivers are not going to be the same.
     
  3. Deluded

    Deluded [H]ard|Gawd

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    VM... It's using your RAM as a HDD. No wonder it's so fast.
     
  4. maddude

    maddude 2[H]4U

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    Are you talking total boot time from first pressing the power button? Loading the BIOS and and RAID setup screens add a fair amount of time to a cold boot. Bypassing those would speed things up a bit.
     
  5. Dario D.

    Dario D. Gawd

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    Actually, since I'm dual-booting, I start my timer the instant I select which OS to load. That's also the point where Virtual Box starts loading, because it doesn't have typical motherboard boot-screens. (each board probably has a different time spent showing those screens)

    No, Windows is stored and loaded from is a regular .vdi file, which sits on my hard drive.
     
  6. Vashypooh

    Vashypooh 2[H]4U

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    VMWare loads the disk into ram as much as possible for swaps.
     
  7. Dario D.

    Dario D. Gawd

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    I don't think that could actually be the case here (at least for bootup. Maybe VirtualBox loads stuff into RAM *after* an OS is loaded) because I have 4 OS's in VirtualBox, so, SuperFetch would have to be stuffing all 4 of their hard drive files into my RAM before I launch... I have 4 GB of RAM, and each hard drive for each OS is larger than that. Also, I know that SuperFetch wouldn't just be loading my most-used hard drive file, because ALL of the OS's load way faster with emulation. (I mean, I could be wrong, but it doesn't SEEM like it to me)
     
    Last edited: Mar 2, 2010
  8. jyi786

    jyi786 [H]ardness Supreme

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    Virtualbox, or any other virtual OS loading program, does exactly that: emulate. Using the lowest standard hardware that is supported by the OS. There is much less for the OS to address; this is the reason why it boots faster. Chances are, once you start actually USING the virtual OS, you will find that it runs a lot slower/quirkier than natively.

    Also, you have to take into consideration that while running an OS, you are already using your hardware to its full potential (i.e. hardware drivers are written for a reason). Booting an OS is quite different from running the OS, as the hardware is forced to run at a basic level, of course, in order to address the rest of the hardware before utilizing it.

    Point in case: the CPU. When you are sitting in your BIOS, your CPU is running almost at full blast. There are no halt commands to stop it. Only when you boot into the OS will you find your CPU usage at a minimum to none, because the OS sends halt commands to the processor.