BIOS - AHCI issue (when using an SSD)

[PeteUK]

Hello,

My question about my HP computer's BIOS is two-fold; this is the second part (first part has already been answered).

The computer is a 64-bit HP Pavilion Media Center TV m7585.uk (model RE467AA–ABU) with ASUS motherboard (P5BW-LA, Rev. 1.05, Basswood) with Intel P965 chipset (I.D. 2812), socket LGA 775, Core2 Duo CPU E6400 @ 2.13 GHz, with 8GB DDR2 RAM and BIOS by Phoenix Technologies 3.03 dated 2006/07/14 (Core Version 6.0) and Win 7 64-bit Ultimate SP1.

Due to its age, the original HDD has been imaged over onto an SSD (Samsung 850 EVO; MZ-75E1T0B), following Samsung's guidelines religiously. I have performed this with my laptop (a few years younger than the desktop) and everything works as it should. The desktop has the following issue:

Upon restart (after imaging the original HDD over onto the SSD), one must enter BIOS and change the settings to AHCI (other options being IDE and RAID) in the Advanced Menu. But alas, Windows OS fails to start and an error message is produced immensely briefly (all relevant images have been posted on my profile, but I do not know if they can be viewed, as I am new on this forum). When starting my HP desktop computer, it informs me that SATA AHCI BIOS is installed, but that "This version supports only Hard Disk and CDROM drives".

I have researched the error and it appears that because this was not a fresh installation of an OS, the AHCI driver needs to be manually switched on in the registry. I am guessing here, but I have found instructions from Microsoft and I have tried this option -- support (dot) microsoft (dot) com / en-us / kb / 922976 of changing the value in that registry key (after making its back-up) and then restarting and changing the BIOS configuration from RAID to AHCI, but when I exit BIOS and it starts loading the OS, exactly the same error message comes up. The system will only work in RAID (which it has originally been set to by HP). Apparently, for the correct and most effective functioning of an SSD (e.g., TRIM etc.), BIOS needs to be set in native AHCI.

Nevertheless, I have attached another Samsung SSD (840 EVO) to see if the motherboard will allow me to install Win 7 when the AHCI setting in BIOS has been chosen (this is recommended for fresh installs of an OS anyway). Even though the same message has come up (that SATA AHCI BIOS is installed, but that "This version supports only Hard Disk and CDROM drives."), the error message has no longer showed up and Windows has loaded and opened fine.

This leads me to believe that there is an issue with the "msahci" and "iaStorV" drivers; specifically with their registry keys, which must have the wrong values, preventing the OS to start with the AHCI setting. I have taken screenshots of the existing SSD's registry values for those keys (images available on my profile) and have named them all "OLD" and then I have taken screenshots of the other SSD's registry values for those two keys (the freshly installed Win 7 OS) and have named them all NEW to easily identify them.

My observation so far is that the "OLD_iaStorV_2" key value ("Enum") is almost identical to the "NEW_msahci_2" (apart from one digit in the PCI\VEN... Data value) and that the "NEW_iaStorV_1" has the start value at 3 instead of 0 (i.e., it is disabled, if I understand this correctly). 

Therefore, I need to know how I must change the registry values to enable the computer to load the OS with the BIOS setting in AHCI, because in RAID, the software cannot even see whether the SSD is connected via SATA or not. Would simply putting 3 in Start in "iaStorV" help (with "msahci" having 0 in Start)? The problem I can see with this is that the old "msahci" has under "Enum" in "0" the Data "Root\LEGACY_MSAHCI\0000". As I do not know anything about how to correctly edit the registry, this probably comes across very simplistic.

Another scenario has also occured to me and that is copying over the NEW registry keys to the old system (same rig, same OS). But, I am concerned that after that, if it goes wrong, the system might not be able to start in either AHCI or RAID: 

In the "old" setting (the current SSD and HDD), the "iaStorV" is set to 0 in Start (i.e., it is active) and the ImagePath is defined as "system32\drivers\iaStorV.sys" and the "msahci" is set to 3 and its ImagePath is defined as \SystemRoot\system32\drivers\msahci.sys

On the other hand, in the "new" SSD setting (fresh install of OS with AHCI setting in BIOS working fine), the new "iaStorV" is set to 3 (i.e., disabled) and its ImagePath is defined as \SystemRoot\system32\DRIVERS\iaStorV.sys and the new "msahci" is set to 0 (Start) and its ImagePath is defined as system32\DRIVERS\msahci.sys 

So those two keys of those two drivers are kind of reversed. 

I should be delighted if one of HP's experts could resolve this for me.

Thank you very much, indeed.

[Mister_Do]

Hi PeteUK,

I think you've actually stated the resolution to this in your description of the problem. 

What I think is happening is that because you are using the same image as your previous hdd and it holds settings for the original configuration of RAID. Really the best, easiest, most quality result will come from installing Windows clean with it set to AHCI. 

Otherwise, you will continue to fight with the settings, or could even end up with a less stable system after messing with all the registery and other settings. Even if you were to get a mostly working system, if ever need to run a Recovery, you would be right back where you started.

My advice is go with what you have already discovered works. I know this means reinstalling drivers and other software, but that would probably take less time and headache in the long run.

[PeteUK]

Hi,

Yes, doing a fresh install of the OS using an AHCI setting in BIOS appears as the simplest solution. The technician who installed my new OS on the system's original HDD three years ago (transferring everyting from the previous 32-bit XP to 64-bit Win 7), with the knowledge that I was changing the OS because I intended to transfer everything onto an SSD, was sadly not very cognizant of these issues and left the BIOS in RAID (hence the current problem).

Nevertheless, I cannot afford to lose much time on this and transferring everything over (instead of cloning) yet again would be prohibitively time-consuming (I have vast amount of programmes, with lots of settings, passwords and data, that I use on a daily basis). 

I suspect that it is simply an issue of those two registry keys. It is obvious that one key for "iaStorV" is active on the current system, but the "msahci" needs to be activated instead. Now the question is to do this correctly. Having the two keys in the right setting from the same rig and the same OS in a working state should assist in correcting the two keys in the current set up. That is my layman's opinion. I have uploaded all the pictures of the two keys in both systems to my profile (hopefully they can be viewed).

I am hopeful that there is an expert who can solve this AHCI driver issue with the relevant registry changes.

Many thanks.

[PeteUK]

PS. The exact error code is as follows:

STOP 0x0000007B (0xFFFFF880009A9928, 0xFFFFFFFFC0000034, 0x0000000000000000, 0x0000000000000000)

I have re-uploaded the screenshot.

[PeteUK]

I have just come across (Microsoft Support site) information that the "msahci" driver requires "atapi.sys miniport" to be loaded during boot as well. This would mean altering another registry key. I have had a look at the "new" system and it is indeed switched on; on the old system, it has Start value at 3, so it is switched off.

[PeteUK]

Hi,

I have changed the Start values in the registry for the following two keys: "msahci" and "atapi" from three to zero, as per Microsoft Support website's suggestion (you may have seen my other later comments relating to this issue). This has resolved the issue of the error and the OS now loads fine, having changed the SATA operation from RAID to AHCI.

Nevertheless, when I ran the Performance Benchmark in Samsung Magician (with and without RAPID Mode), the differences between (all same rig, same OS, using Samsung SSD EVO 840 and 850) the old system (in RAID) [cloned from the original HDD], the new system (in AHCI) [set up purely to figure out the registry keys' settings and for testing] and the old system now in AHCI were not significant, apart from Random Write (IOPS) and Random Read (IOPS) values actually slightly better in the old system in RAID than AHCI (from about 43800 down to 40100; that is, without RAPID Mode)

All in all, basically a waste of time and most probably can be left alone in RAID. I shall drop Samsung a line to see if they will comment on this. Their software should, I think, be able to detect if SATA 2 is being used and if RAID is being used (as it is more or less the same as AHCI) and they should provide better guidelines for users, because the vast majority of them will be lay people like myself. If there is no effect on the functioning of the SSD (TRIM etc.) when in RAID, then they should inform users accordingly and not be telling them to change settings to AHCI (although to be fair, the leaflet said from IDE to AHCI). I read somewhere that any drive (HDD, SSD) that is connected to a SATA port in RAID will automatically default to AHCI mode if it is not part of an actual RAID array.

I hope that this tread will help others avoid messing about with their system unnecessarily and save loads of time. If I get a response from Samsung, I shall update this thread.

Regards

[Mister_Do]

Wow. I'm impressed you got it working with changing all those registery settings. I'm not surprised though that the performance isn' t much improved. Making that many settings changes takes away some of the performance boost you hope to get from an SSD.

I think your detailed scenario of what you went through will definitely help others looking to do something similar. Thanks for posting the results of all your testing. Very educational!

[PeteUK]

Many thanks for your comments!

[mdklassen]

> ASUS motherboard (P5BW-LA) ...

From: http://support.hp.com/us-en/document/c00783637

* 6 SATA connectors

* Each connector supports 1 serial ATA-150 disk drive

A SSD will eliminate the "rotational-delay" inherent in any "spinning" disk-drive, but your SSD, which is capable of data-transfer at "SATA III" speeds, is being "hobbled" by the "SATA One" ports on your motherboard.  Sigh.

I wonder if your performance will improve with an add-in PCI-E-to-SATA-III adapter card, connecting to your SSD ???