Native IDE Mode & AHCI

[ralbrux]

I am in the process of preparing to build a box around the GA-P55A-UD6 mobo running under Windows 7 64-bit.

After reading through the manual I am uncertain about how to use the BIOS setting labeled "SATA Port0-3 Native mode (Intel P55 Chipset) for which the default is to have "Native IDE mode" enabled. The only clear information I have been able to find on this mode is that enables all SATA and PATA resources (Scott Mueller Upgrading and Repairing PCs, 18th edition).

If that is so, I will want to keep this default setting as I will be installing a combination of SATA & PATA devices: 2 Seagate SATA2 HDs and 2 PATA DVD drives. One reason I chose this mobo is so that I could use my current PATA DVD drives together with SATA2 and SATA3 HDds.

This mobo has 3 SATA controllers (with settings in BIOS of course): Intel P55 chipset for up to 6 SATA2 devices; JMB362 chip for up to 2 eSATA devices and Marvell 9128 chip for 2 SATA3 devices.

I will want to set all 3 of these chips to AHCI mode (no RAID planned).

My question is: will there be any problem in having these 3 controller set for AHCI and at the same time maintaing the default "Native IDE mode" setting for SATA Port0-3? Will my SATA HDs and PATA DVD drives be detected properly by Windows 7 64-bit and work and coexist peacefully under such a combinationn of BIOS settings?

I did my best to search this forum, to google the question (also asked Gigabyte GGTS from which I obained only a non-answer) to see if could find an answer to my uncertainty. I did not have any real success, so I hope that my question is not already answered somewhere I didn't find.

Thanks for anybody's help on this.

[Nickel020]

Re: Native IDE Mode & AHCI

AHCI is basically a different mode for SATA devices to operate under, which may providde some slight speed benefits due to Native Command Queuing. The difference is so small though that you can only notice it in benchmarks, so it's not really necessary to enable it when using normal HDs (some SSDs need it).
The PATA devices should still work fine even if you set the Intel P55 SATA ports to AHCI, so you might as well do that.
You can change the setting for a HD from IDE to AHCI before installing Windows but you will get problems if you switch it around after that (Windows won't boot). Also if you use AHCI always remember to switch it on in BIOS after a BIOS update becuase the default setting is IDE.

[ralbrux]

Re: Native IDE Mode & AHCI

Thanks Nickel020 for your reply and the info on AHCI.

Actually my uncertainity is about the SATA Port0-3 setting, and more specifically whether or not the defualt setting in my GA-P55A-UD6 (native ide mode) will in any way conflict with setting my 3 SATA controllers to AHCI mode.

When I've googled or looked in forms for info on native ide mode, there is precious little info out there and most discussions concern problems arising from swithching to AHCI after installing Windows. My research had led me to understand that I need to do the AHCI settings before installing Windows. So I am clear on that issue.

Btw, another thing my research seems to indicate is that beyond the performance issue, AHCI allows for (better ?) hot swapping of SATA drives and that is important for me. My ANTEC case has a front slot for hotswaple SATA HDs and I need to use hot swapping for eSATA as well. I've also read that AHCI provides power management, but I've not seen any detail on that.

Although, given my limited technical know-how, I am not in a position to be sure, I do get the impression from much of the discussion I've come across in the cloud, that there seems to be some confusion around "native ide mode" and SATA controller settings, i.e. IDE, AHCI & RAID. If I'm not mistaken the IDE setting for SATA controller interfaces is quite a another matter than the choice between "Legacy" and "Native" IDE mode of the SATA Port0-3 setting.

I'm still waiting for delivery of my Gigabyte graphics card (GV-R577D5-1GD-B) so in the interval I'm trying to prepare for a build with minimum problems.

I will be setting my SATA controllers to AHCI, so I am hoping that leaving the SATA Port0-3 at it's default setting will not cause me problems.

[Nickel020]

Re: Native IDE Mode & AHCI

Why not set everything to AHCI? This should not cause any problems with your PATA drives, they're not even based on the same controller as the Intel SATA ports, as Intel chipsets have not had PATA since 2007. PATA is always provided by an external chip.
I would enable AHCI and connect the HDs to the Intel ports for the best performance.

[ralbrux]

Re: Native IDE Mode & AHCI

Thanks for your prompt response.

I'm inclined to think that you are right. Certainly nothing in my research indicates the contrary.

So I'll set the SATA controller interfaces to AHCI and leave the SATA Port 0-3 at its default setting.

[Nickel020]

Re: Native IDE Mode & AHCI

Yeah, that's what I'm doing, never had problems with that.

[dimvam]

Re: Native IDE Mode & AHCI

Well I tried to enable AHCI mode but resulted in a BSOD because of not finding IRQ devices table... I really wanted that extra MBytes though!

[mv2devnull]

Re: Native IDE Mode & AHCI

Well I tried to enable AHCI mode but resulted in a BSOD because of not finding IRQ devices table... I really wanted that extra MBytes though!

Of course. You had installed Windows in IDE mode, right? It had drivers for only the IDE controller. That device "disappears" when you change the setting, and an AHCI controller is "added". You'll have no drivers for it. No drivers, no disk access.

Little bit of google (or even search on this forum) should find several howto's on this change in already installed Windows system.

[dimvam]

Re: Native IDE Mode & AHCI

Of course. You had installed Windows in IDE mode, right? It had drivers for only the IDE controller. That device "disappears" when you change the setting, and an AHCI controller is "added". You'll have no drivers for it. No drivers, no disk access.

Little bit of google (or even search on this forum) should find several howto's on this change in already installed Windows system.

Awesome mate, that explains a lot! Thanks for the info!

[ralbrux]

Re: Native IDE Mode & AHCI

A little feed back for Nickel020.

Finally got my Gigabyte HD5770 graphics card late yesterday and finished building the box. Apart from a few hicups (Intel CPU fan cord tangled in with the fan and some hesitations understanding POST messages) all seems to be working well. I succeeded in getting Windows 7 Ultimate 64-bit installation underway - ran out of steam later in the night and will finish it today.

I did, however decide to change my strategy a little by following Intel's suggestion and set the main P55 Sata controller (6 x SATA2) to RAID. RAID, as you know, also sets AHCI. So even though I am not configuring RAID now and don't know if I ever will, since this setting covers my boot disk, in that way I currently have AHCI benefits and can always configure a RAID in the future if I see some interest in it without having to reinstall Win 7 and everything else on the box.

Thanks for your input.