Drive G: intermittently disappears

Britton30 · 07 Apr 2014

The BIOS may or may not enumerate disks in a specific order. There is no direct relationship between the BIOS order, and the order in which Windows numbers the disks. During startup, Windows switches from using the BIOS INT13 support to native Windows drivers to access disks. Windows waits for several seconds for the system disk to enumerate through Plug and Play. When there is a match within the time-out period, normal startup will proceed. Otherwise, the system will trigger a bug check with Stop error code of 0x7B. Windows uses other mechanisms to differentiate disks, as Windows has no control over the disk-numbering process before startup. Windows has no information about any changes to hardware when the computer is turned off. Therefore, Windows initiates its own query for device enumeration.

Yeah, I was wrong there. Still the reasoning to use ports 0 and 1 is still valid to get the benefit of the native chipset controller. Until the new Intel Z87 chipset there was native support for just 2 SATAIII ports, the rest coming from 3rd party once, Z87 can run up to 6. I'm unsure how AMD works.
I have done my own tests and using anything other than the native controller results in very noticeable performance drops, in the time it takes apps to open, rendering an image, transcoding video, to reboot times.

Still all this doesn't explain why the OP's drive drops out.

(jumanji, that thread is so old it's grown a long beard. That was when I had been here just a few months.)

TVeblen · 08 Apr 2014

Yep. Once again we hang around here talking about shoes and fishing while we wait for the OP to tell us if anything we have babbled about solved his problem! I assume he is giving it a few days to see if it is actually over.

And don't get me wrong, I have to have all my hard drives numbered in perfect order! I will completely start a build over and reinstall Windows if I have to. I know I don't need to, but it doesn't help at all when you are OCD!

I'm just saying that the drive order most likely has nothing to do with the OP's problem.

Britton30 · 08 Apr 2014

Yeah you're right Bob, I think I derailed the thread.

I usually point up the need for the OC drive to be disk 0 if it's not, hence me starting that old thread.

Sxcd1 · 08 Apr 2014

I just wanted to give an update to let you know I'm still here. So far I have not had any problem with the drive disappearing. The only think I've changed on the system is changing the position of the boot drive on the Marvell controller from SATA_6 to SATA_7. I did that when I only had on drive it was in position Disk 0. After adding the 2nd drive it went to Disk 1. Not understanding the way it works (thanks for the explainations) I switch the ports but it didn't change the position of the drive in Drive manager. In addition I cleaned the drive letter from the system with drivecleanup utility previously recommend. After installing all the drives the boot SSD is now I think Drive 5. Finally I remove the active flag on what is now Drive I:.

I'm thinking that getting rid of the active flag on drive I: is what fixed the problem. That seems odd to me as you could have a drive with 3 paritions each with an active OS on it booting into each from a boot manager.

If it would help with the discussion about speed and drive position I can change the SSD to SATA_0 and see if it boots faster and run SSD diagnostics before and after to see if the speed decreases from 3 gig/s controller from 6.

Thanks again for the information it's been a great learning experience.

TVeblen · 08 Apr 2014

Good to hear Sxcd1! I've got a good feeling it will stay that way.

Now that you have all your fixed disks in place and recognized you can start adding any external drives back one at a time between reboots. Rebooting may not be entirely necessary but might help keep things in order.
Just remember that hard drives recognized as Removable Drives will have the partition letters change as needed by Windows. For most this is not an issue. I would be wary of any attempt to assign permanent drive letters to Removable Drives as this may make things messy again. For my Removable Drives I give the partitions names but not letters. Works for me, other folks may have a better system.

And we love having folks who will run experiments and post results. That is how we learn what works and what doesn't. So if you want to run performance diagnostics on the different controllers and post results that would be great!

Sxcd1 · 08 Apr 2014

I put the SSD on the SATA_0 controller 3 Gig/s and got this benchmark the original benchmark on the Sata 6 Gigs/s is much faster at reading but not in all write speed categories is posted below it. It seems that I'm much better off using the Marvell 6 gig/s SATA controller vs the native Intel.

TVeblen · 09 Apr 2014

Thanks for the info. Very helpful.

I noticed that the top screenshot (on the SATA0 port) has "pciide - bad" listed.
This would indicate that the SATA controller is set to IDE mode in the BIOS.
The bottom screenshot (on the Marvel port) has "msahci - ok" which indicates that the Marvel controller is set to AHCI mode.

It is recommended that SSDs be run in AHCI mode only. I don't know if this would affect the benchmark scores, but unless you are running any PATA hard drives you should have all of your SATA ports set to AHCI mode for best performance. (Best performance in this case means having the all capabilities of the system available, not that it will improve speed at all).

When the SSD was on the SATA0 port, did Windows start up?

Sxcd1 · 09 Apr 2014

TVeblen said:

Thanks for the info. Very helpful.

I noticed that the top screenshot (on the SATA0 port) has "pciide - bad" listed.
This would indicate that the SATA controller is set to IDE mode in the BIOS.
The bottom screenshot (on the Marvel port) has "msahci - ok" which indicates that the Marvel controller is set to AHCI mode. Turned on AHCI for

It is recommended that SSDs be run in AHCI mode only. I don't know if this would affect the benchmark scores, but unless you are running any PATA hard drives you should have all of your SATA ports set to AHCI mode for best performance. (Best performance in this case means having the all capabilities of the system available, not that it will improve speed at all).

When the SSD was on the SATA0 port, did Windows start up?

When the SSD was on the SATA0 port Windows did start up no problem.

I've adjusted my bios for AHCI mode for all the SATA ports. See attachments
ICH SATA Control Mode [AHCI]
SATA Port 0-3 Native Mode [Enable]
GSATA 8-9 CTRL Mode [AHCI]

SSD Speed improved in some parameters but worse in others. Which SATA port for the SSD would be best SATA_0 or the Marvell 6 gig/s?

TVeblen · 09 Apr 2014

That last AS SSD Benchmark - is that on the SATA0 port?

If the benchmark is better on the SATA 6Gb port then that is the winner.
If the SATA0 port is giving equal performance I think I might want to use that one.

Sxcd1 · 09 Apr 2014

The last AS SSD Benchmark was from SATA0 Port after AHCI was turned on. Maybe it doesn't matter but seq read speeds are 366(6gig/s)-267(3 gigs SATA0), write 165(6 gig/s) - 251(3gig/s SATA0). Other numbers are similar. I'm not sure which benchmark parameter is more important.