Windows 7 Forums
Welcome to Windows 7 Forums. Our forum is dedicated to helping you find support and solutions for any problems regarding your Windows 7 PC be it Dell, HP, Acer, Asus or a custom build. We also provide an extensive Windows 7 tutorial section that covers a wide range of tips and tricks.

Windows 7: AHCI, RAID and 7... is this normal?

26 Aug 2009   #1

Windows 7 Professional 64bit
AHCI, RAID and 7... is this normal?

Hi all,

My current 7100 RC installation sits on two hdd's in RAID 0, provided by the onboard controller; in this case an Intel IHC10R.

I switched the disc mode in BIOS to AHCI; the intent was to reformat and re-install a BSD based system on the second drive, 7 back on the first, and dual boot.

Now, here's the interesting part, I missed the boot prompt and it went into loading windows again, however, it loaded straight into Windows 7.

So although I took the boot order off raid and selected AHCI, it still boots fine!

I don't really understand what went on, but i'd love to know, so I'd like to ask you guys if you can shed any light on this. :)

My System SpecsSystem Spec
26 Aug 2009   #2

Windows 7 Ultimate Edition x64

you're on your own with that one, maybe someone else can answer that one. I don't know why it's still booting after that. lol
My System SpecsSystem Spec
27 Aug 2009   #3

Win7 RTM

My guess as to why you can still boot your HDD was your RAID 0 was not really striping the two HDD's (using both HDD's at he same time for better throughbut). It was just making the two HDD's look like 1 HDD to Windows. It used HDD 1 first, and since you never filled it up, it never needed to use HDD2. Or maybe your RAID 0 was really RAID 1 (mirrored) and you did not notice it.

My $0.02.

BTW, does the Win7 now show your HDD as half the size it was when it was in RAID 0?
My System SpecsSystem Spec

27 Aug 2009   #4

Windows 8.1 Pro RTM x64

My guess would be that you didn't actually have it set up for RAID in the first place. You probably had it set up as a JBOD array. Although this is set up through the RAID configuration, this is as far as it goes. It is not true RAID where you have striping and/or mirroring between the disks. Rather, JBOD allows your system to have a single drive composed of 2 or more individual drives. The total size of this drive is the sum total of all drives in this array. Providing that the amount of data stored does not exceed the capacity of the first disk in this array, you can break it (as you have done) and not notice any difference with it, other than the reduced total capacity.
My System SpecsSystem Spec
27 Aug 2009   #5

Windows 7 Professional 64bit

That's very interesting, thanks guys. ISo even though the the onboard software raid controller was telling me that it was Raid 0, and got me to select the stripe size et al, it was in effect just letting me see the two discs as one volume. That makes alot of sense.

I suppose this also answers why separate controllers from the likes of adaptec are always a better proposition.

I think for me the most interesting aspect of this, and with your replies is that I've been convincing myself that the system is faster etc. etc. and in reality having it all on one disc would have made no difference to speed.... which is further proof of how quick 7 is out of the box.
My System SpecsSystem Spec
27 Aug 2009   #6

Windows 7 Professional 64-bit

Did you actually press ctrll+I during boot to get into the raid setup and create an array?
My System SpecsSystem Spec
27 Aug 2009   #7

Windows 7 Professional 64bit

Oh definitely, set the member discs up, select stripe size, and then in the bios proper set sata configuration to RAID as opposed to ahci or ide !!
My System SpecsSystem Spec

 AHCI, RAID and 7... is this normal?

Thread Tools

Similar help and support threads
Thread Forum
Raid vs ahci?
Whats the difference because, i dont know if this is a issue but when ever i want to install windows 7 i have to set my sata controller to ahci instead of its default settings which is RAID, why do i have to do that?
Installation & Setup
Raid vs AHCI
While experimenting with a USB bootable Macrium Restore thumb drive I created, I was looking in my Bios and noticed the SATA controller was set to Raid. I have only one internal HD. I changed it to AHCI and booted up, got a notice that new drivers were being installed and rebooted. The...
Hardware & Devices
Raid 0 + AHCI?
So I picked up a pair of Corsair Force 120Gb SSD drives and set them up in RAID 0. Figured I could just slap them in, load the AMD RAID drivers then do a clean install of Win 7. Which Iíve done and everything seems to be working fine. Now reading about the performance benefits when setting your...
Hardware & Devices
Raid, AHCI or IDE
I have a friends HP system I'm fixing for him. His hard drive died, totally inaccessible (750GB SATA 3 Seagate). I ordered the recovery DVD and a new hard drive. In BIOS, the SATA controller can be set to Raid, AHCI or IDE. My question is, which is the right one to use. It was set to Raid but...
Installation & Setup
Ahci & raid
I recently bought 2 120GB OCZ Vertex 2 SSDs, a new CPU heatsink, and 2 new video cards (5850s). I was running my Windows 7 64 on 2 WD velociraptors in RAID0 prior to rebuilding my system. I never had any issue with Windows installation. I tried setting up my system to where my SSDs would be in...
Installation & Setup

Our Sites

Site Links

About Us

Find Us

Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

© Designer Media Ltd

All times are GMT -5. The time now is 09:39.
Twitter Facebook Google+