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betterdan
12-10-09, 11:23 AM
I've got my computer set now to use the 2 drives in my sig in IDE mode. Would it be worth it to use them in AHCI mode? If I want to do that I just have to first edit the registry to enable the AHCI drivers in Win 7 (http://support.microsoft.com/kb/922976) then reboot and change it to AHCI mode in the bios right?
Would there be much of a performance increase at all?
I've never used AHCI mode so I was just wondering.

grey_1
12-10-09, 11:27 AM
I didn't notice much difference at all. Ymmv of course.

Just be aware if you set AHCI you can't change your mind after the fact. Mine wouldn't boot in IDE comp. afterwards, so any other drives also had to be AHCI.

EDIT: fwiw I installed Win 7 using IDE compatibility mode and it's still much snappier than Vista 64 was in AHCI.

S.SubZero
12-10-09, 11:50 AM
It's one of those things where under "certain" conditions there may be an improvement in access, but it really is YMMV as stated. The only thing I noticed on my gaming rig going from IDE mode in Vista to AHCI in Win7 is the stupid "safely remove hardware" icon now shows, since AHCI enables hot-plug for SATA devices. I can unplug my C: drive now? Thanks for letting me know. -.-;

grey_1
12-10-09, 11:58 AM
It's one of those things where under "certain" conditions there may be an improvement in access, but it really is YMMV as stated. The only thing I noticed on my gaming rig going from IDE mode in Vista to AHCI in Win7 is the stupid "safely remove hardware" icon now shows, since AHCI enables hot-plug for SATA devices. I can unplug my C: drive now? Thanks for letting me know. -.-;

Heh, yeah, forgot to mention that :lol:

Redshirt #24
12-10-09, 12:07 PM
I also went from IDE mode in Vista to AHCI in 7 after a motherboard swapout...I haven't done anything really intensive yet (pending task: copying about 1TB of collected stuff from two separate SATA drives to a single larger one), but it definitely seems a bit snappier in general. I'm not complaining too much.

DiscipleDOC
12-10-09, 12:29 PM
I also went from IDE mode in Vista to AHCI in 7 after a motherboard swapout...I haven't done anything really intensive yet (pending task: copying about 1TB of collected stuff from two separate SATA drives to a single larger one), but it definitely seems a bit snappier in general. I'm not complaining too much.

What is your WEI Score?

betterdan
12-10-09, 01:02 PM
I didn't notice much difference at all. Ymmv of course.

Just be aware if you set AHCI you can't change your mind after the fact. Mine wouldn't boot in IDE comp. afterwards, so any other drives also had to be AHCI.

EDIT: fwiw I installed Win 7 using IDE compatibility mode and it's still much snappier than Vista 64 was in AHCI.

Are you sure? In that case anyone using AHCI couldn't have any IDE devices. In that Microsoft link I posted, it says this "This issue affects only the boot drive. If the drive that you change is not the boot drive, you do not experience this issue."


In the bios I believe it lets you select each individual drive if they are AHCI or IDE.

Also couldn't you just reverse what you did before in the registry and set it back to IDE in the bios to boot up the C drive as an IDE device again?

Since it seems Microsoft is saying you can enable AHCI on other drives and it won't affect your boot drive or make you have to edit the registry,I may try to enable it on my other hard drive (the Seagate) and see what difference it makes if at all.

Q
12-10-09, 01:11 PM
If you use Media Center to record TV, I would highly suggest turning on AHCI.

logan
12-10-09, 01:20 PM
I recall having problems booting some CDs or flashing/tuning HDD firmware with AHCI enabled and maybe even some problems burning CDs in Linux a while back, but I use AHCI quite a bit at work for hotswap with software raid. I had a few eSATA enclosures at home and AHCI was needed to hotplug those, otherwise you had to boot up with them already connected and powered on.

AHCI also enables NCQ for your drives, but it's generally recommended to disable this on each device when they're used in a software raid on Linux (dunno about other OS').

grey_1
12-10-09, 01:22 PM
Are you sure? In that case anyone using AHCI couldn't have any IDE devices. In that Microsoft link I posted, it says this


In the bios I believe it lets you select each individual drive if they are AHCI or IDE.

Also couldn't you just reverse what you did before in the registry and set it back to IDE in the bios to boot up the C drive as an IDE device again?

Since it seems Microsoft is saying you can enable AHCI on other drives and it won't affect your boot drive or make you have to edit the registry,I may try to enable it on my other hard drive (the Seagate) and see what difference it makes if at all.

Boot drive is what I meant, should have been more clear. IOW if I install using AHCI I cannot change that back to IDE later.

I never did explore changes in the registry though.

Redshirt #24
12-10-09, 02:04 PM
What is your WEI Score?
5.9 overall, same as the HD (a modest Maxtor 500GB)--everything else is/was either 7.5 or 7.8--which is a small bump up from Vista (5.2, IIRC).

betterdan
12-10-09, 02:24 PM
Well I checked my Bios manual and it says if I select AHCI mode it affects all SATA connections. I thought it would let you select each individual connection and set them as either AHCI or not. So what Grey said is right, if I do select it then all SATA drives will have to support AHCI.
Hmm I'll have to see if I can set it back and turn AHCI off or not in case I don't like that mode. I would hate to enable it then have troubles and find out I can't turn it back without reinstalling the OS. Anyone know if that is for sure possible?

agentkay
12-10-09, 03:24 PM
I've dealt with this a few days ago when I got my new motherboard. After modifying the registry to enable the AHCI driver, I changed the setting in the bios and then reinstalled the chipset drivers to recognize the new devices. I personally didn't like that mode, most of my drives were running in Multiword DMA2 mode and seemed a bit louder as well. While they were not much slower on their own, file transfers between the drives were slower though. I was able to switch back to IDE mode without issues. It still loads the AHCI driver but everything is back at IDE and UltraDMA Mode 5. Kind of interesting how these drives actually worked in UltraDMA Mode6 on my old motherboard (i965 chipset) but I don't think there is a big different between those two.

I might actually try the Raid mode, it could possibly work better than the AHCI one.

Redeemed
12-10-09, 04:22 PM
Interesting topic, betterdan.

I recently put my i7 rig together... and for some reason it just seems a bit slower than my Q6600 setup was (not in games, at the desktop and basic stuff). I've been wondering if it's my hard drive.

Not sure what it's set to in the BIOS- I've got everything at default currently. What would you guys suggest it be set to for optimal performance? My drive is a 500GB Samsung SATA 3Gbps, 16MB cache, 7200RPM- forget the drives exact model number. :o

nekrosoft13
12-10-09, 05:10 PM
It's one of those things where under "certain" conditions there may be an improvement in access, but it really is YMMV as stated. The only thing I noticed on my gaming rig going from IDE mode in Vista to AHCI in Win7 is the stupid "safely remove hardware" icon now shows, since AHCI enables hot-plug for SATA devices. I can unplug my C: drive now? Thanks for letting me know. -.-;

that is one of the benefits of AHCI, much better hot swap support.

Redeemed
12-10-09, 06:02 PM
And I recall something about some SATA 3Gbps drives having a jumper, that you have to reposition it and you'll often times get better performance? Or am I completely wrong here...? :o :( :lol:

nekrosoft13
12-10-09, 06:27 PM
some drives have a jumper, but it is only to enable 3Gbps or disable it

Redeemed
12-10-09, 06:38 PM
some drives have a jumper, but it is only to enable 3Gbps or disable it

Oh... and how do I know if my drive has the jumper, and what it should be set to? Manufacturer's website?

Also, about the AHCI... should it be enabled?

grey_1
12-10-09, 07:02 PM
Oh... and how do I know if my drive has the jumper, and what it should be set to? Manufacturer's website?

Look? :lol:
Also, about the AHCI... should it be enabled?

If you will be hot swapping then yes. if not then you probably won't need it. I really didn't see any difference on my P5E.

Others have though, may be up to trial and error.

Redeemed
12-10-09, 07:06 PM
Look? :lol:

If you will be hot swapping then yes. if not then you probably won't need it. I really didn't see any difference on my P5E.

Others have though, may be up to trial and error.

:o :lol:

Well, most any SATA drive I've seen has a jumper, which is why I asked the question. I'd assume that the manufacturer would have documentation on their website though. Just need to look at the model of my drive and head to Samsung's website. :)

As to AHCI, I really have no idea what it is for- hence my "ignorant" questions. :o :(

I believe it is disabled, if I recall. So I'll just leave it as is then. :)

grey_1
12-10-09, 07:09 PM
:o :lol:

Well, most any SATA drive I've seen has a jumper, which is why I asked the question. I'd assume that the manufacturer would have documentation on their website though. Just need to look at the model of my drive and head to Samsung's website. :)

As to AHCI, I really have no idea what it is for- hence my "ignorant" questions. :o :(

I believe it is disabled, if I recall. So I'll just leave it as is then. :)

:D

I would just check the documentation and go from there. Most average users like me probably won't need it.

betterdan
12-10-09, 07:11 PM
Yea I'm gonna leave it as IDE also, I'm happy with the performance as it is so no need to go screwing with it like I always like to do and usually end up putting things back like I had them in the first place (thinks of recent ribbon cable to round IDE cable and back to ribbon cable adventure) :D

Redeemed
12-10-09, 07:27 PM
:D

I would just check the documentation and go from there. Most average users like me probably won't need it.

When all else fails, RTFM- right? :D :lol:

I've never really looked into this, any time I get a new hard drive I just install it and go- never worried about jumpers since... hmm... think it was my old slot A Athlon 750. :D :lol:

grey_1
12-10-09, 07:37 PM
When all else fails, RTFM- right? :D :lol:

I've never really looked into this, any time I get a new hard drive I just install it and go- never worried about jumpers since... hmm... think it was my old slot A Athlon 750. :D :lol:

LoL, I didn't want to say it... :o :D

Absolution
12-13-09, 02:02 AM
Enabling ACHI will turn on native command queuing and could potentially increase random read/writes. I've also read that it can potentially decrease performance in some areas.

IMO it is worth it. The performance benifits seem to outweigh the potential decreases.

If you have an nVidia chipset though, I'd stay away. I've always had problems with stability (BSOD) and was always annoyed that that 'safely remove hardware' icon never went away. Hot plug never worked either and required a reboot for it to be detected. . .

My P45/P55 boards have had a good implementation of ACHI and I haven't had any issues with it. None of my hard drives are listed as 'safely remove' and I haven't had any stability issues. Hot plugging actually works too with my external enclosure along with a bare 3.5" drive I have laying around.