cancel
Showing results for 
Search instead for 
Did you mean: 

AHCI Mode

Moderator
Moderator
Posts: 18,074
Thanks: 2,617
Fixes: 192
Registered: 06-04-2007

AHCI Mode

Not sure if this should be Hardware or Windows...
After changing my HDDs due to a failure I was left with the following internal drives:
3xSATA HDD
1xSATA DVD RW
2xIDE HDD
Although the MB has 5 SATA ports (1,2,3,5 & 6) it seems that 5 & 6 only work in raid or AHCI mode.
I have set the BIOS option to AHCI mode and have set about installing W7 64 bit. So far it booted from DVD and W7 installation has started and it did show all avaliable drives (I think).
Would I meet any issues running in AHCI mode permanantly? I understand that to revert to IDE mode would need a W7 re-installation but just wondered about stability running in AHCI. Did a Google searvh where quite a few people complained that they could no longer use their SATA DVD-RW but I don't seem to be suffering from this.
Any help appreciated.
Thanks.

Forum Moderator and Customer
Courage is resistance to fear, mastery of fear, not absence of fear - Mark Twain
He who feared he would not succeed sat still

6 REPLIES
Community Veteran
Posts: 38,460
Thanks: 1,027
Fixes: 62
Registered: 15-06-2007

Re: AHCI Mode

That sounds like a motherboard/bios problem.
Is your problem RAIDor AHCI as RAID isn't ACHI dependent
Which motherboard are you using and which SATA ports work - on board chipset or secondary chipset - often 4 are from the on board chipset and 2 from the secondary chipset with different drivers
Moderator
Moderator
Posts: 18,074
Thanks: 2,617
Fixes: 192
Registered: 06-04-2007

Re: AHCI Mode

Sorry, I didn't actually state the problem Embarrassed
When in IDE mode I could only see any of the drives that were connected to SATA ports 1,2 & 3. No matter what configuration of cables, power connecter or drive nothing iconnected to ports 5 or 6 would show under the BIOS. A little research and reading of the manual indicated my problem was related to the fact that ports 5 & 6 didn't support IDE and were only for AHCI or raid. I don't wish to use RAID and there seems no way to set ports 5 & 6 only to AHCI.
The MB is Asus M4N78.
Windows 7 64 bit has finished installing and I can see all 5 drives + DVD RW without any problems within Computer. USB stick also showuing OK. I was more concerned about reliability and stability in AHCI mode as I have never had any need to use it before (in fact, never knew about it till today).
As an aside I see a 6th HDD drive icon marked System Reserved (FSmiley 61.8MB free of 99.9MB. Clicking on it an it shows as empty (not configured to show System files yet). I don't remember such a drive under W7 32 bit. What is it for and can I hide it from display?

Forum Moderator and Customer
Courage is resistance to fear, mastery of fear, not absence of fear - Mark Twain
He who feared he would not succeed sat still

Community Veteran
Posts: 38,460
Thanks: 1,027
Fixes: 62
Registered: 15-06-2007

Re: AHCI Mode

AHCI mode doesn't seem to cause problems - I have been running it for several years
Looking at the manual for the M4N78  there seems to be 3 options in bios SATA, RAID or AHCI is yours a different model
Note that the last SATA drive is an eSATA
The system reserved is part of the Windows install http://www.shivaranjan.com/2009/05/11/how-to-prevent-windows-7-from-creating-a-hidden-recovery-syste... if there is some unallocated space on the drive
Moderator
Moderator
Posts: 18,074
Thanks: 2,617
Fixes: 192
Registered: 06-04-2007

Re: AHCI Mode

Quote from: Oldjim
AHCI mode doesn't seem to cause problems - I have been running it for several years

So far so good Smiley
Quote
Looking at the manual for the M4N78  there seems to be 3 options in bios SATA, RAID or AHCI is yours a different model
Note that the last SATA drive is an eSATA

What's not clear from the manual is whether the AHCI only affects SATA 5 & 6 or all of them - I'm assuming all.
Not sure you're correct about the last SATA be eSATA as there is a separate eSATA on the back.
Quote
The system reserved is part of the Windows install http://www.shivaranjan.com/2009/05/11/how-to-prevent-windows-7-from-creating-a-hidden-recovery-syste... if there is some unallocated space on the drive

What I've now realised is that this System Reserved (ZSmiley drive is actually from the W7 32bit installation on the other HDD. Although it's only 100MB I still don't like it showing. I've never bothered with partitions before so... will a reformat of that HDD remove it or do I have to do some 'jigery pokery' first?

Forum Moderator and Customer
Courage is resistance to fear, mastery of fear, not absence of fear - Mark Twain
He who feared he would not succeed sat still

Community Veteran
Posts: 38,460
Thanks: 1,027
Fixes: 62
Registered: 15-06-2007

Re: AHCI Mode

The manual states that there are 5 SATA connectors, 1 IDE connector and 1 eSATA connector and I suspect I misread your earlier post
The motherboard chipset nForce 720D natively supports 6 SATA drives and 2 IDE drives but Asus have used one of the SATA connections for the eSATA port on the back.
Removing that partition seems to have nasty side effects http://answers.microsoft.com/en-us/windows/forum/windows_7-performance/can-i-delete-the-system-reser... but this tells you how to do it http://social.technet.microsoft.com/Forums/en-US/w7itproinstall/thread/5271e9b6-4775-43f9-bfcd-b4f08...
Moderator
Moderator
Posts: 18,074
Thanks: 2,617
Fixes: 192
Registered: 06-04-2007

Re: AHCI Mode

Ahh, that explains where SATA 4 is Smiley
Thanks for the links. I'll get on to that as soon as I've sorted other issues Shocked

Forum Moderator and Customer
Courage is resistance to fear, mastery of fear, not absence of fear - Mark Twain
He who feared he would not succeed sat still