What is AHCI?

Just think of it as native SATA rather than IDE emulation. Basically it allows additional fuctions such as hot swap SATA, and Native Command Queueing (assuming the disk supports it).

I dont know if SSD Trim's are limited to AHCI or if they use a command that is compatible with IDE emulation.
 
Say for example; you had the crucial ssd with the latest firmware on achi mode and on windows 7, it would have trim enabled. If you then put it to "ide" mode, you wouldn't have trim enabled. You would have to use a program called "wiper" that does the same job as trim but manually. Its like a defragger for the ssd, as you can't use the windows defragger.
 
Is that really true that TRIM doesn't work in Windows 7 unless you use AHCI? :confused:

I thought TRIM currently just doesn't work if you use RAID but it does work with both IDE and AHCI under Windows 7? Certainly on my Crucial CT128M225 SSD with the v1819 firmware and using IDE drivers, the following command entered into the Command Prompt (Cmd) under Administrator mode returns a 0 which indicates that TRIM *is* enabled.

fsutil behavior query disabledeletenotify

If the value returned is 1 then TRIM is not enabled.

What confuses me somewhat is that TRIM may well be enabled on my system but how do I really know that it is actually working?
 
Ben-Irvine93 said:
Say for example; you had the crucial ssd with the latest firmware on achi mode and on windows 7, it would have trim enabled. If you then put it to "ide" mode, you wouldn't have trim enabled.
Click to expand...

I don't think, even with the latest Crucial firmware, that automatic TRIM is supported. You have to run Crucial_Wiper whether in IDE or AHCI mode.
 
Darren1967 said:
fsutil behavior query disabledeletenotify

If the value returned is 1 then TRIM is not enabled.

What confuses me somewhat is that TRIM may well be enabled on my system but how do I really know that it is actually working?
Click to expand...

I `think` that command just shows you if Windows 7 is sending TRIM commands to the SSD controller, your SSD might not do anything with these commands. The only util I've seen that tells you if its enabled definately is crystaldiskinfo.
 
all i know is you change to achi from IDE before you install windows7 if you do it after the install you get blue screen on boot :D
 
Just a quick question. I've just changed from IDE mode to AHCI in the BIOS as I get better read and write speeds with my SSD in this mode. However it seems to take a lot longer to shutdown now, is that normal? In IDE mode it would shutdown in a few seconds, with AHCI is seems to hang for about 30 seconds before finally switching off.

Edit: Ignore, seems to be working fine after a few restarts, weird
 
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The new 1916 firmware is out for the Crucial M225 SSD by the way. It supports both TRIM and Garbage Collection. I installed it last night and so far it seems to be working well. If I run C_Wiper.exe now (not needed but I thought I'd try it) then it finishes in under 5 seconds now compared with 2-3 minutes before with the 1819 firmware. Hopefully the firmware's own GC is equally as effective.
 
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