AHCI Questions

boozie

Senior member
Oct 12, 2006
486
1
81
I am building a computer with a 128 GB SSD and a 1 TB HD using Win 7 64-bit. I know before I install Win 7 I want to enable AHCI in bios, what I had some questions about is does AHCI mostly pertain to the drive the OS is on? Do you enable it for each individual drive you are using? I am planning in plugging in my old 500 GB HD to move data from it to the SSD and/or 1 TB HD, there won't be any issues because it's from an old computer not using AHCI will there?

Probably pretty dumb questions, but I just wanted to understand it better.

[e] Also to prevent a 2nd thread, is it important to install the OS with only the SSD plugged in or can I have another HD in at the same time and just specify install to SSD?
 

VirtualLarry

No Lifer
Aug 25, 2001
56,326
10,034
126
[e] Also to prevent a 2nd thread, is it important to install the OS with only the SSD plugged in or can I have another HD in at the same time and just specify install to SSD?

You can do that, but chances are, Win7 will create its boot files onto the HD. You don't want that. So if you can, plug in ONLY the main boot SSD first, do the install, and then attach the HD afterwards.
 

boozie

Senior member
Oct 12, 2006
486
1
81
So I set up the new PC, activated AHCI, and installed Win 7. Is there any reason I should pop in the CD the SSD came with? I'm not running raid. I assume trim is already working and that I don't need to install RST.
 

VirtualLarry

No Lifer
Aug 25, 2001
56,326
10,034
126
So I set up the new PC, activated AHCI, and installed Win 7. Is there any reason I should pop in the CD the SSD came with? I'm not running raid. I assume trim is already working and that I don't need to install RST.

You should be fine then.
 

boozie

Senior member
Oct 12, 2006
486
1
81
Thanks again. And now for the hat trick.

This doesn't belong here but it's a quick one:

My front panel has an AC'97 and HD Audio plug, which one should I be using (P67 mobo if it matters). Also I found a 4 prong plug labeled speakers that is on its own coming from the front panel. I am assuming this is in the event I can't plug AC'97/HD Audio in and can be ignored for my case.
 

ImpulsE69

Lifer
Jan 8, 2010
14,946
1,077
126
Thanks again. And now for the hat trick.

This doesn't belong here but it's a quick one:

My front panel has an AC'97 and HD Audio plug, which one should I be using (P67 mobo if it matters). Also I found a 4 prong plug labeled speakers that is on its own coming from the front panel. I am assuming this is in the event I can't plug AC'97/HD Audio in and can be ignored for my case.

The 4 prong one is the internal "pc speaker" and mostly unrelated to your front audio. It's for the speaker you mount in your case (well..they used to..I haven't used one in years).
 

Cannyone

Member
Sep 6, 2007
35
0
0
I am building a computer with a 128 GB SSD and a 1 TB HD using Win 7 64-bit. I know before I install Win 7 I want to enable AHCI in bios, what I had some questions about is does AHCI mostly pertain to the drive the OS is on? Do you enable it for each individual drive you are using? I am planning in plugging in my old 500 GB HD to move data from it to the SSD and/or 1 TB HD, there won't be any issues because it's from an old computer not using AHCI will there?

Probably pretty dumb questions, but I just wanted to understand it better.

[e] Also to prevent a 2nd thread, is it important to install the OS with only the SSD plugged in or can I have another HD in at the same time and just specify install to SSD?
For clarification, and information... I'd like to add the following.

First off, AHCI is a mode for your motherboard's SATA controller. So if you turn it on it affects all drives connected to that controller. And you want it turned on because it allows your system to use the "Advanced" features of your hard drive, and improves performance. The alternative is IDE mode which emulates an older standard and is most useful when you are using an Old Hard Drive.

It used to be, with previous Operating Systems, that you had to load AHCI drivers from a floppy disk. And you would tell the OS to stop and look for these drivers by pressing "F6" at the beginning of the OS installation. So, at times, you might hear these drivers referred to as "F6 drivers". Now Windows 7 doesn't require them. It will load a set of drivers when the controllers of most Intel chipsets are set to AHCI mode. Though it is a good idea to load the correct Intel drivers after the OS installation has completed.

You can have multiple HDDs installed and specify with drive you want the OS installed on. But there is a catch when you are using "bare drives" (meaning they don't even have a partition on them). When drives don't have partitions the motherboard's BIOS handles them differently. This can result in cases where Windows loads the OS onto one drive and the "boot files" onto another.

You need to be sure you've connected the OS drive to your SATA "0" port (the first port). Then you should make sure you partition both drives, without actually installing the OS. (You can use the OS installation DVD to do this...). After you partition the drives you need to shutdown the computer, and when you restart it enter BIOS and confirm that your Boot Order is correct. Plus, at the same time, you can confirm how the drives are physically connected.

For example: on my systems (all set up for AHCI) it indicates that one of the drives is "P0" followed by a model/serial number. That is the drive connected to "port 0". And in my case I have drives showing "P1" and "P2". This can be a bit confusing if you use multiple drives of the same make and capacity. But otherwise its a clear indication of which drive is connected to each port (its too bad that most motherboard's manuals don't clearly describe how ports are ordered - but we just have to live with that fact).

The bottom line is that both Drives don't have to be formatted to install the OS, but you want to have both drives partitioned, so that BIOS can assign Drive letters. Plus, with late model hard drive or SSD, you really do want to use AHCI mode. Windows 7 makes it easy, so there's no longer an excuse.

Oh, and Windows 7 has support for things like "Trim" and "Garbage Collection". So you don't have to install that stuff. You just need the drive controller set to "AHCI" mode for them to work.

Thanks again. And now for the hat trick.

This doesn't belong here but it's a quick one:

My front panel has an AC'97 and HD Audio plug, which one should I be using (P67 mobo if it matters). Also I found a 4 prong plug labeled speakers that is on its own coming from the front panel. I am assuming this is in the event I can't plug AC'97/HD Audio in and can be ignored for my case.

As ImpulsE69 pointed out the "4 prong plug" is for a board speaker. It gives you the "POST" beep or multiple beeps when some conditions for boot up are not met. So boards have this speaker built in and others do not. I always connect this if the motherboard doesn't have a speaker built in.

As for the Front Panel Audio connector its best to use the "HD Audio" plug, and the vast majority of motherboards have a connector for this cable (at least IF they have onboard sound). I personally tend to "prune" the "AC'97" plug off and tape up the wires. But I don't like to leave stuff like that dangling as a matter of personal taste.

In closing I'd just like to wish you good luck with your new build. :)