GUIDE - Enabling AHCI mode AFTER Windows 7 Installation

Discussion in 'SSD and HDD storage' started by Hilbert Hagedoorn, Jan 19, 2010.

  1. Pill Monster

    Pill Monster Banned

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    Yes the SSD is just like any other SATA drive so if your OS is on the SSD you need to set the BIOS to boot from hard disk.

    If you want to boot from the old OS and it was installed in IDE mode then you'll need to switch back to IDE mode in BIOS.
    You can only boot from AHCI if the OS was installed when the disk was in AHCI mode, if you get my meaning.
     
  2. Multivac

    Multivac New Member

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    Slightly different situation

    Hi Guys,

    I'm not sure if my situation fits the guide described in this thread and I'd really appreciate the advice.

    My setup:

    2x Western Digital WD3000HLFS (300GB Velociraptor Drives)
    1x CD SATA drive on a
    Motherboard: Asus Rampage II Extreme board.
    OS: Windows 7 Ultimate 64bit

    I've been trying to get my external drive enclosures working - They take SATA drives and have SATA output. (See image of them here https://dl.dropbox.com/u/3222505/20120825_203637%20%28Medium%29.jpg )
    Windows is refusing to pick up these drives at all even after reboot or hot-swap. They are not even being picked up on the BIOS.
    The only thing I could think of is that I need to change the SATA configuration from IDE to AHCI.

    My questions are:

    1) Will changing to AHCI help me with picking up these drives or is this another topic?

    2) If the registry change fails does this break the OS install permanently? (i.e should i backup)

    3) Is it possible to get these external drives to work as a hotswap system? I'd like to archive all my old junk onto these things...
     
  3. Castaa

    Castaa New Member

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    Thanks for the AHCI tip. This was a major factor in improving my low SSD Crucial M4 performance.
     
  4. lmimmfn

    lmimmfn Ancient Guru

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    Dammit i wish i read this when i installed my SSD lol
     

  5. giozera

    giozera New Member

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    Hello
    I recently got my Alienware M18x R2 and updated to Kingston HyperX 3K SSD, I installed fresh win 7 on raid mode since I didn't know benefits of AHCI for SSD. now after I learned I tried this guide and after I did changes in Registry I rebooted to bios and changed to AHCI saved and restarted but it will get blue screen with error : 0x0000007b. it means that os can't get boot device. than I went to bios and changed to RAID again restarted and OS boots properly, I went to registry and seems changes are there. any ideas why this guide did not work for me?
    thanks
     
  6. BigBlockTowncar

    BigBlockTowncar Ancient Guru

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    What about the JMB363 and JMB362? Mine are set for IDE.

    My SATA was already set for AHCI (I did it when I first installed the OS onto my SSD).

    Will it increase any performance to switch the JMB363/362 to AHCI even though the SSD does not use the PCIE--but for other devices...GPU?
     
  7. fxsimba

    fxsimba New Member

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    Guys, i need some urgent help..

    Tried the above process step by step, and my screen is stuck on "loading operating system ..." screen, and doesnt move forward..

    I switched my setting back to IDE .. And still the same .. Could some one please help me get back to normall .. Im panicking now.

    Thanks

    (Ps:i am writing this from my ipad)
     
  8. Rich_Guy

    Rich_Guy Ancient Guru

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    ^ Tried safe mode to change the reg back to the default 3.

    Just had to do this for my new SSD (thought i was running AHCI), worked fine, so thanks Hilbert :)
     
  9. airbud7

    airbud7 Ancient Guru

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    I have used this guide at least 5 times in the last 3 years, works every time...Thanks Boss...:thumbup:
     
  10. adw99

    adw99 New Member

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    Thank You

    I wanted to thank you for the Sticky, it worked perfectly with my Samsung Evo

    I was stumped and then i found AHCI needed to be activated before installing the OS!! my head sunk.

    My Windows score has gone from 7.2 to 7.4 and the SSD is flying and even my new 3TB and my quite old 250GB drives are better (not much but....)

    As always good people save the day and make us smile

    Cheers
     

  11. hold_on_tight

    hold_on_tight Member

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    What is NCQ ?
     
  12. IAmGhostDog

    IAmGhostDog Maha Guru

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    Quoted
     
  13. Tocean1

    Tocean1 New Member

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    Hi all,

    I have tried to use this guide for my AMD board the Asus M4a88TD-V Evo Usb 3. It does not work, or other guides that edit the registry. I have tried the windows automatic fix which did not work either.

    I cannot figure out how to switch to AHCI for my SSD :( Any help would be greatly appreciated. Please let me know what information I need to give anyone to be able to help me out!
     
  14. Pill Monster

    Pill Monster Banned

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    The guy who posted that at OCN is wrong, NCQ is not used on SSD's.
    It's a feature for Hard Disk controllers that allows data to be retrieved in the order it lies on the platter not the order it was requested.
     
  15. Pill Monster

    Pill Monster Banned

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    Hi, prob stupid question but did u turn on AHCI in bios after doing the reg edit?
     

  16. FatBoyNL

    FatBoyNL Maha Guru

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    NCQ is used on lots of SSDs. It's used for multi-tasking in general; grouping commands and such.
    Please see Samsung explaining things here: http://www.samsung.com/global/busin...isite/SSD/global/html/about/whitepaper02.html

    "NCQ
    AHCI also affects the ability of Samsung’s SSDs to reach their maximum Random QD32 performance. This is because AHCI is required for Native Command Queuing (NCQ) to function. Because SSDs enjoy extremely fast speeds, storage is no longer the bottleneck of a PC system. NCQ helps an SSD deal with situations where it finds latency on the host, a phenomenon unheard of with traditional HDDs. Additionally, NCQ allows the SSD controller to process commands in parallel, improving performance and reducing latency."
     
  17. Tocean1

    Tocean1 New Member

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    Hi Pill Monster,

    Yes, I did enable AHCI after making the changes to the registry. I just get a lovely BSOD.
     
  18. Tocean1

    Tocean1 New Member

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    I got it to work, just moved my sata cables around. It prompted the drivers to install, thanks for trying to help.
     
  19. Pill Monster

    Pill Monster Banned

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    ^Good to hear. :)




    Yeah but note they only mention QD32 which is at the extreme end of the scale and absolute best case scenario. QD4 is more realistic on typical PC (non server)...even then there's only a 70mb/s difference between QD1 and QD32 according to Anandtech....not surprising considering the near 0 latency with SSD's. It's a nice sales brochure tho....



    My earlier post came out not the way it was supposed to lol. I was in a hurry and didn't even bother using punctuation....

    To clarify:
    OCN info was somwhat inaccurate because;
    NCQ is not some "important feature" for SSD's; Command Queuing is not unique to AHCI; or introduced with AHCI either -it was around before AHCI on ATA controllers (TCQ)... and a couple of other points I won't go into.....

    Btw I said "not used" on SSD's - should have been "not useful" on SSD's"....:p Sorry bout that..
     
    Last edited: Jul 8, 2014
  20. FatBoyNL

    FatBoyNL Maha Guru

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    Pill, what features ARE useful on SSDs from your point of view? Just TRIM perhaps? ;)
    NCQ still seems quite useful to me (and my SSDs), please see http://en.wikipedia.org/wiki/Native_Command_Queuing#NCQ_in_solid-state_drives
     

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