Change IDE to AHCI in BIOS - Much better performance

[jimbo45]

Hi all
It will mean a fresh CLEAN install of Windows I'm afraid but if you have decent SATA disks change the default setting in the BIOS from IDE to AHCI.

It really WILL improve system performance --one of my big bugbears on any discussion on performance is how the I/O subsytem (generally Disks) is forgotten - yet on most home computers the I/O subsystem is often the real cause of dreadful performance.

You'll have to do a windows CLEAN install as the system will BSOD if you just change the BIOS so you won't be able to run the installer from within Windows itself. (If you can you are very lucky).

It won't effect any Virtual machines you may have however (apart from improving disk performance).


Cheers
jimbo.

 

[pparks1]

I went back and forth between AHCI being on and being off on my new box that I built in July. Honestly, with almost ever task I did and with any benchmarking tool, I didn't see any real performance gain with AHCI enabled.

Unfortuantely, with AHCI on, I do have about an 8 second delay on each boot as the storage controller initializes. And since I do boot daily, and it was costing me 8 seconds which I didn't pick back up elsewhere, I just run with AHCI disabled.

 

[Zardoc]

I don't use it either. Intel recommends and enables it when running with raid. Does give better performance, I don't know. I stopped using raid for a while.

 

[swarfega]

I have mine set to raid.

 

[jimbo45]

Hi there
you have to use I/O bound tasks --otherwise it won't make a huge amount of difference unless you have RAID as well.

However with LARGE photoshop files and > 1 TB size disks the I/O throughput is significantly faster than with the IDE interface - and don't forget before SSD gets cheap enough for us mere mortals to use SATA-2 will be upon us.

The other thing with AHCI is that you don't get all sorts of problems when hotplugging etc etc.

Cheers
jimbo

 

[swarfega]

Whats I/O bound tasks and is it something i have to enable or install a driver for?

 

[v104hx]

btw u dont need to reinstall windows. u can enable/disable ahci in reg. reboot change bios. done.

ok i thought i edit this post and let u guys know how to do so. incase anyone cares at all.

- run regedit.
- go to HKEY_LOCAL_MACHINE/System/CurrentControlSet/Services/Msahci
- right-click Start in the Name column, and then click Modify.
- In the Value data box, type 0, and then click OK.
- exit the registry editor.

This requires a reboot. so do it. enter ur BIOS Settings and enable AHCI. On boot Windows will detect the changes made and reinstall needed drivers. Requires another reboot.

Once thats done ur done. AHCI enabled

 

[nate42nd]

I went back and forth between AHCI being on and being off on my new box that I built in July. Honestly, with almost ever task I did and with any benchmarking tool, I didn't see any real performance gain with AHCI enabled.

Unfortuantely, with AHCI on, I do have about an 8 second delay on each boot as the storage controller initializes. And since I do boot daily, and it was costing me 8 seconds which I didn't pick back up elsewhere, I just run with AHCI disabled.

I have been advised by Patriot to use IDE while using their SSDs. They seem to think it will "cause fewer problems" I DO think AHCI will give better performance however. I have had a lot of trouble getting an answer to this. It's a good idea to do your own benchmarks. It may vary from system to system.

 

[toughbook]

What is the down side to disabling AHCI? My BIOS doesn't have a setting for it I don't think.

That is one thing I have never taken the time to fully understand. Raid, Raid 0, Raid 1. I just don't get it. Whenever I have loaded an OS I have never seen or been given a choice for any Raid selections? Hell, I could be running Raid 999 for as far as I know

 

[nate42nd]

What is the down side to disabling AHCI? My BIOS doesn't have a setting for it I don't think.

That is one thing I have never taken the time to fully understand. Raid, Raid 0, Raid 1. I just don't get it. Whenever I have loaded an OS I have never seen or been given a choice for any Raid selections? Hell, I could be running Raid 999 for as far as I know

RAID is a Redundant array of independent disks. There are several flavors. I would just leave your BIOS alone if you're not sure what to do and things are working okay.

 

[swarfega]

btw u dont need to reinstall windows. u can enable/disable ahci in reg. reboot change bios. done.

ok i thought i edit this post and let u guys know how to do so. incase anyone cares at all.

- run regedit.
- go to HKEY_LOCAL_MACHINE/System/CurrentControlSet/Services/Msahci
- right-click Start in the Name column, and then click Modify.
- In the Value data box, type 0, and then click OK.
- exit the registry editor.

This requires a reboot. so do it. enter ur BIOS Settings and enable AHCI. On boot Windows will detect the changes made and reinstall needed drivers. Requires another reboot.

Once thats done ur done. AHCI enabled

Mine is currently set to 3, so not sure what that means.

 

[Zardoc]

Nate, What's your verdict on SSD??

I have raid on my Qosmio G35. What bothers me is the trouble when a drive craps out.

AHCI has not nade a difference for me either and yeah it is cool if you hotplug.

I have a regtweak for those who want to enable AHCI.

OH, and please, Always use at your own risk.

 

[Antman]

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\msahci]
"Start"=dword:00000000
"Type"=dword:00000001
"ErrorControl"=dword:00000003
"ImagePath"=hex(2):5c,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,\
74,00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,44,00,52,\
00,49,00,56,00,45,00,52,00,53,00,5c,00,6d,00,73,00,61,00,68,00,63,00,69,00,\
2e,00,73,00,79,00,73,00,00,00
"Group"="SCSI Miniport"
"DriverPackageId"="mshdc.inf_x86_neutral_3f3676f4c0e7d884"

Is this for 64-bit as well?

Why the variation between the two suggestions?

go to HKEY_LOCAL_MACHINE/System/CurrentControlSet/Services/Msahci

 

[v104hx]

yes works in x64 aswell. if urs is set to 3 this usually means ur running IDE. U have to set this value to 0 (zero) to enable ahci. also need to enable it in bios on next reboot or Win will BSOD. the reg file provided by Zardock imo is for x86 systems only. (->mshdc.inf_x86_neutral_3f3676f4c0e7d884 = 32bit driver)

This is the x64 equivalent: mshdc.inf_amd64_neutral_a69a58a4286f0b22

about the difference between the two suggestions. Not sure tbh. Only did it my way and that worked for me. also i've tried it on x86 and also x64 systems. works. This is nothing new btw. Works in XP and Vista too :->

 

[Antman]

yes works in x64 aswell. if urs is set to 3 this usually means ur running IDE. U have to set this value to 0 (zero) to enable ahci. also need to enable it in bios on next reboot or Win will BSOD. the reg file provided by Zardock id for x86 systems obviously. (->mshdc.inf_x86_neutral_3f3676f4c0e7d884 =32bit driver)

This is the x64 equivalent: mshdc.inf_amd64_neutral_a69a58a4286f0b22

about the difference between the two suggestions. Not sure tbh. Only did it my way and that worked for me. also i've tried it on x86 and also x64 systems. works.

Thank you for the timely response.

This is not a leet site. Please use a more common language so we can separate your meaning from your typos.

 

[swarfega]

yes works in x64 aswell. if urs is set to 3 this usually means ur running IDE. U have to set this value to 0 (zero) to enable ahci. also need to enable it in bios on next reboot or Win will BSOD. the reg file provided by Zardock imo is for x86 systems only. (->mshdc.inf_x86_neutral_3f3676f4c0e7d884 = 32bit driver)

This is the x64 equivalent: mshdc.inf_amd64_neutral_a69a58a4286f0b22

about the difference between the two suggestions. Not sure tbh. Only did it my way and that worked for me. also i've tried it on x86 and also x64 systems. works. This is nothing new btw. Works in XP and Vista too :->

Thanks, sounds like I need to disable it then since I dont have any IDE drives. I dont want to use ahci though, its currently set to raid in bios.

 

[HammerHead]

To raid or not to raid

I have ran a raid 1 config on my last two rigs. Twice I have had a problem. I tried to install a new disk and was not successful. I resorted to other backups etc. to solve the problem. I am cosidering on the new Win 7 install to scrap raid and go to another scheme for saving my operating system in case of a catastrophic failure.

Cons for raid:
speed reduction
uses up an extra disc

I think if I took the extra disk and put it in a dock and cloned the os to it once in a while. In the event of failure I could just replace the disk.

Does this sound reasonable?

 

[Zardoc]

Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\msahci]
"Start"=dword:00000000
"Type"=dword:00000001
"ErrorControl"=dword:00000003
"ImagePath"=hex(2):5c,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,\
74,00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,44,00,52,\
00,49,00,56,00,45,00,52,00,53,00,5c,00,6d,00,73,00,61,00,68,00,63,00,69,00,\
2e,00,73,00,79,00,73,00,00,00
"Group"="SCSI Miniport"
"DriverPackageId"="mshdc.inf_x86_neutral_3f3676f4c0e7d884"

Is this for 64-bit as well?

Why the variation between the two suggestions?

go to HKEY_LOCAL_MACHINE/System/CurrentControlSet/Services/Msahci

My bad Antman.

I should have mentioned that driver ID points to X86. The right value for X64 is mshdc.inf_amd64_neutral_a69a58a4286f0b22 as pointed out.

CurrentControlSet or CurrentControlSet001 won't make a difference. So let's stay on the same line. CurrentControlSet.

From Microsoft KB922976

During the Windows 7 or Windows Vista installation process, any unused storage drivers are disabled. This behavior speeds up the operating system's startup process. When you change the boot drive to a driver that has been disabled, you must enable the new driver before you change the hardware configuration.

For example, assume that you install Windows Vista or Windows 7 on a computer that contains a controller that uses the Pciide.sys driver. Later, you change the SATA mode to AHCI. Therefore, the drive must now load the Msahci.sys driver. However, you must enable the Msahci.sys driver before you make this change.

I added the notes to reg file.

 

[Antman]

Good work Zardoc. This thread requires more prominence.

 

[nate42nd]

Nate, What's your verdict on SSD??

I have raid on my Qosmio G35. What bothers me is the trouble when a drive craps out.

AHCI has not nade a difference for me either and yeah it is cool if you hotplug.

I have a regtweak for those who want to enable AHCI.

OH, and please, Always use at your own risk.

I will be honest, I have loved my SSD. I contacted Patriot with a MINOR problem I was having with slow writes for flash player temp files and they immediately told me to send them the drive and sent me a new one. I'm not quite sure it needed to be RMAd but I am just setting up the new one today. Other than that issue i have LOVED it. I have always run mine in AHCI mode but Patriot says to use IDE so I am going to try that for a while.

I believe during install you have to be in AHCI if you plan to switch back and forth between the two so I plan to do that tonight. I would love if someone could confirm this. I guess if you are in AHCI Windows 7 will install the driver automatically and you can switch. If you are in IDE during install you will BSOD if you try to switch to AHCI.

This is my understanding.

I would HIGHLY recommend getting a solid state disk Zardoc