Note on archived topics.
09-21-2016 12:01 PM
09-21-2016 04:53 PM
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.
09-21-2016 05:35 PM
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.
09-22-2016 08:29 AM
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.
09-22-2016 01:27 PM
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.
09-22-2016 01:43 PM
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!
10-20-2016 05:40 PM
> ASUS motherboard (P5BW-LA) ...
* 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 ???