[nmX.Memnoch]

Some of you have seen me mention Asus' lack of AHCI support on the P5K series of motherboards...specifically those that don't use the ICH9R southbridge. Well...Intel has finally put some information on their site as to why those boards don't have AHCI support.

Quote

ICH9, ICH8, ICH7 and ICH6-based chipsets, as well as ICH5 and ICH5R-based chipsets, do not use AHCI.

Moral of the story? If you want full AHCI support for your SATA devices on an Intel southbridge, get one that uses the RAID version of the southbridge even if you aren't going to use the RAID functions. If you're wondering what AHCI gives you...without it you won't have support for NCQ or Hot Plug features. There are other features, but those are the two most used features.

This post has been edited by nmX.Memnoch: 21 September 2007 - 06:44 PM

[ripken204]

yep, and i have the raid one and it does have AHCI.

[puntoMX]

Thank you nmX.Memnoch, as you can see it wasn’t ASUS his fault, and I posted that many time before.

Again, thank you for the tip, this info is very welcome for ANY one who wants a new iNTEL based system with FSB of 1333MHz / 45nm CPU die.

[nmX.Memnoch]

Well...unfortunately it took an outcry from the community to get something added on Intel's site. From what I've read (and I'll admit I have no first-hand knowledge or on-hands experience with it) many of the other tier-1 motherboard OEM's that have P35/ICH9 based motherboards (without RAID) have AHCI support in their BIOSes. I know that we have some Dell OptiPlex GX520 machines at work that have the AHCI option in the BIOS...and they don't have onboard RAID.

To be honest I'm still not sure exactly what to believe, but it's right there in black and white on Intel's site...and it is their chipset after all.

[puntoMX]

I know that the P5K without RAID supports NCQ for example... But you are right, something IS fishy here...

[nmX.Memnoch]

puntoMX, on Sep 22 2007, 06:02 PM, said:

I know that the P5K without RAID supports NCQ for example...

No, it doesn't. Asus removed the AHCI option three or four BIOS revisions back. Their stated reason for this is that ICH9 doesn't support AHCI. And according to the link I posted above, they're right. Since NCQ is a feature of AHCI, there is no NCQ support without AHCI support.

Quote

Native Command Queuing (NCQ) is a feature supported by Advanced Host Controller Interface (AHCI). It allows ATA drives to accept more than one command at a time and dynamically reorder the commands for maximum efficiency. NCQ, when used in conjunction with a hard drive that supports NCQ, can increase storage performance on random workloads.

In order to take advantage of NCQ, you need:

• Intel® Matrix Storage Technology software
  
• Hard drive(s) that supports NCQ
  
• Intel® chipsets using a controller hub that supports AHCI

This post has been edited by nmX.Memnoch: 23 September 2007 - 10:57 PM