How to Enable/Check TRIM/AHCI in Windows 7

RAM GUY · #1 04-09-2010, 05:45 PM

There is an awesome Blog about SSD's in general on MSDN that is good reading to help understand the basics.

Quote:

How to enable TRIM Command in Windows 7 with a Solid State Drive

To enable or disable TRIM Command, you will need to open an Elevated Command Prompt window.

How To Open an Elevated Command Prompt window: Click on Start Orb > Type "CMD.exe" in Search box > Right click on "CMD" and select "Run as Administrator" (If you receive a prompt confirmation, click YES)

How to Enable TRIM Command

In the Elevated command Prompt windows, type the following:

fsutil behavior set disabledeletenotify 0

How to Disable TRIM Command

In the Elevated command Prompt windows, type the following:

fsutil behavior set disabledeletenotify 1

How do I know if TRIM is working in Windows 7?

In the Elevated command Prompt windows, type the following:

fsutil behavior query disabledeletenotify
Results explained below:
DisableDeleteNotify = 1 (Windows TRIM commands are disabled)
DisableDeleteNotify = 0 (Windows TRIM commands are enabled)

How to enable AHCI in Windows 7 after Instalation:

There is one way to fix this, although you need to have knowledge of registry editing. The detailed steps from Microsoft are as follows:

1.Exit all Windows-based programs.
2.Click Start, type regedit in the Start Search box, and then press ENTER.
3.If you receive the User Account Control dialog box, click Continue.
4.Locate and then click the following registry subkey:
HKEY_LOCAL_MACHINESystemCurrentControlSetServicesMsahci
5.In the right pane, right-click Start in the Name column, and then click Modify.
6.In the Value data box, type 0, and then click OK.
7.On the File menu, click Exit to close Registry Editor.

After this you’ll have to restart your computer, go to BIOS and enable AHCI. When you log in to Windows again, you’ll notice the installation of drivers for AHCI. Another restart will be required to finish the driver installation.

These steps are provided at your own risk and not suggested unless you know and understand the risks. You will want to make sure the controller driver and MB BIOS support this option before you enable it

Some information taken from www.msdn.com, www.microsoft.com, and www.ithinkdiff.com, and www.ssdtechnologyforum.com.

snowstar · #2 05-22-2010, 09:04 AM

Ramguy,

Checking if trim is enabled worked flawlessly! Thanks, I was worried when I saw a scheduled defragmentation that trim was not enabled.

Does the scheduled defrag seem correct for a recognized ssd?

Poisonsnak · #3 05-22-2010, 01:21 PM

Quote:

Originally Posted by snowstar

Ramguy,

Checking if trim is enabled worked flawlessly! Thanks, I was worried when I saw a scheduled defragmentation that trim was not enabled.

Does the scheduled defrag seem correct for a recognized ssd?

In my experience on Windows 7 scheduled defrag is more of a system-wide setting, so if it says "next scheduled defrag is 05/26/2010" then that means the next system defrag is that day.

I have one system with 1 ssd and 3 regular hdds, and under the "last run" column it shows the date for the 3 hdds, but for the ssd it says "never run" even though the system has been up and running for some months now. I believe it uses the windows experience index score for each hard drive to determine whether or not it is an ssd and doesn't rely on things like trim (my case is a perfect example - I have an X64 in this system running the old non-trim firmware and Windows still knows not to defrag it).

gunrunnerjohn · #4 07-04-2010, 12:14 PM

I did the test for TRIM and it appears to be working.

C:\Users\Owner>fsutil behavior query disabledeletenotify
DisableDeleteNotify = 0

When I open Regedit and look at the value you mention to enable it, I find.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\msahci]
"Start"=dword:00000003

If zero is really the proper value, how do I explain the difference in the results? Is there any way I can actually verify TRIM is truly working?

fab_hofmann · #5 07-17-2010, 08:44 AM

I don't have a command named FSUTIL ?! it isn't working...

Synthohol · #6 07-17-2010, 09:27 AM

ya gotta have it somewhere, i even have it in XP!! it's in your \windows\system32 folder
http://commandwindows.com/fsutil.htm

gunrunnerjohn · #7 07-17-2010, 09:39 AM

If not, your installation is probably corrupt. In that case, try running: SFC /SCANNOW

fab_hofmann · #8 07-17-2010, 10:22 AM

ok I think i missed something. it works now

PrObE · #9 08-27-2010, 02:11 AM

i would like to add a point to this that i have found to be easiest and most reliable way to have/confirm TRIM is working;

Simply log off windows, also make sure all other users are logged off if multiple, and leave the computer idling for a couple of hours or overnight.

i can physically see the difference in ATTO when i log-on again so for my system this is a confirmed way of having TRIM working the most effectively.

I have seen this posted randomly, but i feel this method is a little "underestimated" :)

Cheers,

Yellowbeard · #10 08-27-2010, 02:31 AM

Quote:

Originally Posted by PrObE

i would like to add a point to this that i have found to be easiest and most reliable way to have/confirm TRIM is working;

Simply log off windows, also make sure all other users are logged off if multiple, and leave the computer idling for a couple of hours or overnight.

i can physically see the difference in ATTO when i log-on again so for my system this is a confirmed way of having TRIM working the most effectively.

I have seen this posted randomly, but i feel this method is a little "underestimated" :)

Cheers,

This is a good distinction. The methods outlined in this thread merely show that TRIM is ENABLED. Your suggestion is good because you can actually verify and show proof of TRIM WORKING. Good post IMO.

TTune · #11 10-07-2010, 02:08 AM

Hello, all.

I've got a P256 which is certainly faster than my original hard drive.

My problem is that I'm using a Sony VAIO laptop - and there's no obvious way to flip AHCI on within the BIOS. (It's a Sony thing - this disabling of features like VT and AHCI).

So - Even though I've set the registry and 'enabled' TRIM - without AHCI I'm toast, right? Any advice would be appreciated.

Thanks!

gunrunnerjohn · #12 10-07-2010, 11:55 AM

Get a different laptop?

TTune · #13 10-07-2010, 01:25 PM

Quote:

Originally Posted by gunrunnerjohn

Get a different laptop?

Occams Razor: popularly interpreted as "the simplest explanation is usually the correct(Best) one". Yes - a new laptop would be the answer.

Clearly, however, you are not aware of she-who-must-be-obeyed. I can get away with hours of putzing about but not a simple trip down to the Best Buy.

Plan B: Get AHCI working "somehow". Anyone know how to flip that bit on a VAIO BIOS? (Assumes I NEED it to get TRIM working.)

So the real question is; Will TRIM work ONLY if MSAHCI.sys is loaded?

Yellowbeard · #14 10-07-2010, 01:42 PM

You have to have a driver that can pass the TRIM command AND have the controller AHCI mode. The newest Intel driver will pass the TRIM command (on Intel controllers of course) and the Microsoft driver will of course pass it. But, if you can't do AHCI mode on your controller, it's a moot point.

Yellowbeard · #15 10-07-2010, 01:45 PM

FYI, the P series has its own garbage collection function which works at the controller level and is completely independent of the OS. So, not having TRIM is not the end of the world in this case.

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