# IDE vs AHCI



## MxPhenom 216 (Dec 29, 2010)

When i installed my SSD i didnt know that if i set it to ACHI in the bios i get more performance out of it. Its set to IDE. Is it worth the complete reinstall of changing it to ACHI??


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## Solaris17 (Dec 29, 2010)

hmm i know for HDD's it isnt as iv personally done it....but i think your deff supposed to for ACHI weather its worth it im unsuire about. I think your only REALLY supposed to for SSD's because of trim or some shit. As for speeds im not to sure maybe a few mb/s i would have to brush up on it again. of course at the end of the day it comes down to how much you feel like backing up your stuff because an install of 7 via thumbdrive will only take like 10min.

EDIT:

http://benchmarkreviews.com/index.php?option=com_content&task=view&id=505&Itemid=38


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## GENTLEMEN (Dec 29, 2010)

I'd set it to AHCI to check if the performance boosts. It did for me, but boot time went up quite a bit (ahci loading after bios).


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## Widjaja (Dec 29, 2010)

ACHI is the later and supposed to be better but in my experience with other machines I have found it doesn't give much of a performance boost.


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## TheLostSwede (Dec 29, 2010)

FYI, the ACHI boot bit goes away with UEFI...


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## MxPhenom 216 (Dec 29, 2010)

thelostswede said:


> fyi, the achi boot bit goes away with uefi...



uefi??


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## slyfox2151 (Dec 29, 2010)

http://en.wikipedia.org/wiki/Extensible_Firmware_Interface

not a bios, but UEFI.


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## MxPhenom 216 (Dec 29, 2010)

slyfox2151 said:


> http://en.wikipedia.org/wiki/Extensible_Firmware_Interface
> 
> not a bios, but UEFI.



Oh yeah i heard about that. isnt that coming out like in a couple years??


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## Widjaja (Dec 29, 2010)

slyfox2151 said:


> http://en.wikipedia.org/wiki/Extensible_Firmware_Interface
> 
> not a bios, but UEFI.


Off topic:-
Extensible is a word?!

Carry on....


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## {JNT}Raptor (Dec 29, 2010)

With an SSD....most report crappy performance before switching over to AHCI.
Your not getting the full speed of your SSD without AHCI.....but "most" would need to reinstall the OS in order to switch the setting in bios.....you can google how to do it without a reinstall......I've seen it done myself.

Bottom line though......AHCI will unleash your beast....IDE will not.

Hope it helps.


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## MxPhenom 216 (Dec 29, 2010)

{JNT}Raptor said:


> With an SSD....most report crappy performance before switching over to AHCI.
> Your not getting the full speed of your SSD without AHCI.....but "most" would need to reinstall the OS in order to switch the setting in bios.....you can google how to do it without a reinstall......I've seen it done myself.
> 
> Bottom line though......AHCI will unleash your beast....IDE will not.
> ...



alright well im probably going to do it tomorrow so


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## btarunr (Dec 29, 2010)

You need AHCI for TRIM. Without TRIM, your write performance will degrade over time.


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## MxPhenom 216 (Dec 29, 2010)

btarunr said:


> You need AHCI for TRIM. Without TRIM, your write performance will degrade over time.



alright thanks.

So tomorrow when i go to do it. just should i go into the bios change it to ACHI and then boot from the windows disk to reinstall??


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## btarunr (Dec 29, 2010)

You can actually switch between IDE and AHCI modes in Vista/7 (with the OS installed). Microsoft has a Knowledge Base article on that. Just backup your 4chan treasure before you try it.

http://support.microsoft.com/kb/922976


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## Mussels (Dec 29, 2010)

AHCI doesnt give much in the way of performance boosts, its features.

NCQ and hot swap being the main two.


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## Millennium (Dec 29, 2010)

btarunr said:


> You can actually switch between IDE and AHCI modes in Vista/7 (with the OS installed). Microsoft has a Knowledge Base article on that. Just backup your 4chan treasure before you try it.
> 
> http://support.microsoft.com/kb/922976



I did this and it worked fine. Don't bother with the reinstall this takes like 2 minutes


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## RejZoR (Dec 29, 2010)

Mussels said:


> AHCI doesnt give much in the way of performance boosts, its features.
> 
> NCQ and hot swap being the main two.



And slightly lower CPU utilization.


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## Solaris17 (Dec 29, 2010)

btarunr said:


> You can actually switch between IDE and AHCI modes in Vista/7 (with the OS installed). Microsoft has a Knowledge Base article on that. Just backup your 4chan treasure before you try it.
> 
> http://support.microsoft.com/kb/922976



thats not a good idea. that simply changes what the OS thinks its installed as that does not enable the features that would be eneabled when nativly installed under AHCI.


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## animal007uk (Dec 29, 2010)

Sorry if its been mentioned but you do not have to reinstall the OS when you set it the AHCI mode, just make sure you install the driver in windows first then when you make the bios change the pc should boot just fine. (there might be a reg edit you need to do first aswell)

I know it works for me but might not work for others.

I will try and find the info i used a while ago and post the link here.



Solaris17 said:


> thats not a good idea. that simply changes what the OS thinks its installed as that does not enable the features that would be eneabled when nativly installed under AHCI.



Worked fine here tho i dont have an SSD but my normal drive defo had all fetures enabled after i installed the driver, thinking bout it now i defo had to do a regedit to.


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## Mussels (Dec 29, 2010)

animal007uk said:


> Sorry if its been mentioned but you do not have to reinstall the OS when you set it the AHCI mode, just make sure you install the driver in windows first then when you make the bios change the pc should boot just fine. (there might be a reg edit you need to do first aswell)
> 
> I know it works for me but might not work for others.
> 
> ...



the trick i usually do is to set up a second SATA controller - be it onboard, a PCI-E or PCI card, and move the OS drive to that.

Instsall drivers, shut down, move OS to the newly installed SATA controller, configure the old one to AHCI,boot windows on the new controller - install AHCI drivers, shut down, put back on regular controller.


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## cilindrox (Dec 29, 2010)

btarunr said:


> You need AHCI for TRIM. Without TRIM, your write performance will degrade over time.



Not entirely true, AHCI only helps in some synthetic benchmarks. In fact, I have the de facto IDE option in my laptop with a Mushkin Callisto Deluxe and TRIM is working perfectly.
Enabling AHCI will only stress your SSD even more without any real tangible benefits - besides the WPI, of course.

Here's a link (couldn't find the OCZ report) - http://windows7forums.com/windows-7-hardware/18767-ahci-ssds.html#post78921


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## animal007uk (Dec 29, 2010)

Mussels said:


> the trick i usually do is to set up a second SATA controller - be it onboard, a PCI-E or PCI card, and move the OS drive to that.
> 
> Instsall drivers, shut down, move OS to the newly installed SATA controller, configure the old one to AHCI,boot windows on the new controller - install AHCI drivers, shut down, put back on regular controller.



I got blue screens after setting my bios to AHCI mode so i set it back to ide then loaded windows 7 up, installed AHCI drivers made a regedit and restarted the pc, Went into bios set it back to AHCI mode and it booted fine. never had to change the sata port or anything but like i said it might not work for everyone.


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## btarunr (Dec 29, 2010)

Solaris17 said:


> thats not a good idea. that simply changes what the OS thinks its installed as that does not enable the features that would be eneabled when nativly installed under AHCI.



Hot-switching IDE to AHCI (with OS installed) enables NCQ on HDDs that support it. So I'm sure TRIM gets enabled. When you switch from IDE to AHCI, Windows redetects the hard-drive (or in this case, the SSD) and controller it's installed on (despite booting from the same drive).


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## Millennium (Dec 29, 2010)

Since no-one has posted the actual instructions (ok maybe the MS ones ) here is what I did and it worked 100%!

http://forums.guru3d.com/showthread.php?t=313676


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## animal007uk (Dec 29, 2010)

Millennium said:


> Since no-one has posted the actual instructions (ok maybe the MS ones ) here is what I did and it worked 100%!
> 
> http://forums.guru3d.com/showthread.php?t=313676



 I was going to post info but the beers and wine have kicked in so i cant be arsed now but when i feel more normal i will post the info i said i would hehe.

happy new year all.


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## MxPhenom 216 (Dec 29, 2010)

btarunr said:


> You can actually switch between IDE and AHCI modes in Vista/7 (with the OS installed). Microsoft has a Knowledge Base article on that. Just backup your 4chan treasure before you try it.
> 
> http://support.microsoft.com/kb/922976



I need to go into the bios and change as well right??


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## Millennium (Dec 29, 2010)

After making the change, yes.


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## MxPhenom 216 (Dec 29, 2010)

Millennium said:


> After making the change, yes.



theres a problem when i start of the regedit thing there is no Open HKEY_LOCAL_MACHINE / SYSTEM / CurrentControlset / Services


EDIT: nvm got it


I should probalby install my sata drivers for my motherboard right now huh??

EDIT; okay evga doesnt have sata drivers for my board. they have sata6 drivers for their others


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## MxPhenom 216 (Dec 29, 2010)

nvidiaintelftw said:


> theres a problem when i start of the regedit thing there is no Open HKEY_LOCAL_MACHINE / SYSTEM / CurrentControlset / Services
> 
> 
> EDIT: nvm got it
> ...




EDIT: just rebooted and got into windows with a window installing everything for SATA. Sweet!

now just rebooted again because i had to. and it seems to be all good. actually seems to be a bit more snappy believe it or not


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## Millennium (Dec 29, 2010)

great glad it worked! some claim a fresh install sets up windows different though so maybe look into it or just do a clean reinstall in a few months...


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## MxPhenom 216 (Dec 29, 2010)

Millennium said:


> great glad it worked! some claim a fresh install sets up windows different though so maybe look into it or just do a clean reinstall in a few months...



I think itll be fine.


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## Batou1986 (Dec 29, 2010)

Surprisingly my buddy just set it in the bios after moving the drive from an old pc.

Booted once in ide mode let windows set all the new hardware up, rebooted switched to ahci  set the boot drive , windows did the same re detecting of the HDD hardware this was on win7 x64 Pro AMD platform.

It can make a big difference imo i see about 25Mb/s increase in transfer speeds on WD VR


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## MxPhenom 216 (Dec 29, 2010)

Batou1986 said:


> Surprisingly my buddy just set it in the bios after moving the drive from an old pc.
> 
> Booted once in ide mode let windows set all the new hardware up, rebooted switched to ahci  set the boot drive , windows did the same re detecting of the HDD hardware this was on win7 x64 Pro AMD platform.
> 
> It can make a big difference imo i see about 25Mb/s increase in transfer speeds on WD VR



yeah i saw that much in just reviews from switching to ACHI


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## MxPhenom 216 (Dec 29, 2010)

i wish i would have ran a test in IDE mode in HDtune and then did one now to see the increase


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