SSD in SCSI mode instead of AHCI using X79 chipset

lucbujold · 01 May 2014

HI to you,

I'm running with an Asus P9X79 Pro, BIOS updated to the latest version and a Corsair Neutron 120GB...
The SATA mode in BIOS is set to AHCI.

But in Windows 7, all drives (1 SSD, 1 WD HDD and 1 Seagate HDD, and Asus DVD Drive) are seen as SCSI devices...

I tried to use only windows 7 64 bits native AHCI drivers and I got the same things as I used the IRST drivers provided by Asus... As I've done many search on the web about AHCI and X79 chipset I've found so many issues and no real answer, I'm deseperatly need help.

As I want to get all the performance and stability of my system I just want to make sure that everthing work as it is design to...

thanks in advance for your help...

pbcopter · 02 May 2014

That is normal for those controllers/drivers to report SCSI. The drives are functioning normally as AHCI.

If you are connected to the Intel controller, what IRST driver version are you using?

lucbujold · 03 May 2014

The RST 12.8.0.1096...

I know that those drivers can be reported as SCSI but why?
is it because the X79 use the SCSI and ACHI the same way or is it because there is no good or specific drivers?

And as I saw many issues with the RST, could it be better to use some native windows 7 AHCI drivers?

Other little question, as you said that it is operating as an AHCI, how can I make sure that all benefits of AHCI are effectives?

If the BIOS sees 125GB instead of 120GB, could it be a clue of a SSD problem?

essenbe · 03 May 2014

IRST (Intel Rapid Storage Technology) is Intel's raid driver, but it also contains IaSror.SYS which is Intel's AHCI driver. It is the only way to get it that I know of. MSAHCI is Microsoft's AHCI driver. I have found that I seem to get better performance slightly from using the Intel driver. If you will go to device manager and expand the IDE ATA/ATAPI Controllers, you should see one or the other there. If it says MSAHCI or has an Intel chipset AHCI driver listed, you are in AHCI mode. Those are your Sata port controllers, if it says you have the AHCI drivers, then you are in AHCI mode.

pbcopter · 04 May 2014

Go to this site and download and install the drivers under Intel RAID/AHCI Drivers C. 1. called

Universal 64bit Intel RST AHCI & RAID driver v11.2.0.1006 mod by Fernando

(The only mod done is to let the installer recognize the X79)

To me, these are the best drivers for the X79 and the drives are not ID'd as SCSI.

Other AHCI and RAID Drivers » Recommended AHCI and RAID Drivers

lucbujold · 05 May 2014

Thanks Pbcopter...!

It works...!

But I'm not able to do firmware upgrade of the SSD... I was'nt able to do before... I've read the it was not possible to do it when the drive is seen as SCSI... So my goal was to get it seen as an ATA: goal achive.

I'm thinking that Corsair may have remove the new m208 firmware (I have m206), or I have some issue with the drive...

and I have another question: why a WD black sata3 (pluged in a Sata3 port) is slower than a Seagate Barracuda sata3 (pluged in a Sata 2 port).

WD: Write: 90MB/S Read: 96 MB/S
Seagate: Write: 140MB/S Read: 182 MB/S.
My SSD Corsair: Write: 306MB/S Read: 500 MB/S

tested with AS SSD

Theses results are the same after the installation of the new drivers (by Fernando)

pbcopter · 05 May 2014

Is one of your drives connected to the Marvell controller? If so, that might be the difference. That controller will not yield the same speeds as the Intel.

What drivers are you using for the Marvell?

lucbujold · 06 May 2014

The Western Digital was on the SATA1 (6G) Port...
And the Seagate was on the SATA2 (3G) port...

They are using the Intel controller...
I have a DVD writer (sata III) on the SATA3 (3G) port...

I did'nt tried to use the Marvel controller as I was thinking that it was only for raid configuration...

pbcopter · 07 May 2014

I really can't say why you are getting those benchmarks.

What do you get if you reverse the connections on the WD and Seagate?

essenbe · 07 May 2014

I really don't think it matters whether they are connected to a sata 2 or a sata 3 as long as it is controlled by the Intel controller. I do not believe and have never seen a mechanical hard drive that can come close to saturating the bandwidth of sata 2. You must remember, it was only the past few years that SSDs were capable of that.