Windows 7 hangs Drive numbers change

[CyberSimian]

Brian K wrote:
> BIU can do everything that BIBM does with regard to booting multiple operating
> systems.

What I particularly like about BIBM is its EMBR concept. It allows you to hide completely one operating system from another. Provided that you use 1 MiB filler partitions to ensure that there are no unused entries in the MBR(s), this is very nearly 100% safe. (There is one circumstance where overwriting could occur, but so far I have never seen that happen with any release of Windows.)

BIBM has a "Hide" setting for a partition, and I would expect that BIU does too, but as far as I know, all that happens is that a bit flag is switched "on" somewhere in the MBR or EFI. It is entirely up to the booted OS to decide whether it is going to obey the setting of that bit flag, or trample all over the "hidden" partitions in the belief that it has a god-given right to do so. Do you trust Microsoft to obey the setting of the bit flag? I don't.

Brian K wrote:
> It can restore a metadata image of a fresh Win10 installation in 2 seconds.

Crikey!

-- from CyberSimian in the UK

[Brian K]

CyberSimian wrote:
>
> BIBM has a "Hide" setting for a partition, and I would expect that BIU does
> too,

Yes, it does. The GPT Partition Type is changed from Normal Data to BootIt Hidden. Microsoft OS can't see data in these partitions. In Disk Management these partitions show as "Healthy (Primary Partition)" and can't be assigned a drive letter. I accept that is different from partitions on an EMBR disk.

[CyberSimian]

AGH1965 wrote:
> Even if you would install it in the other slot, you should have the possibility to
> select either SATA or x4 PCIE mode. At least that is how I interpret the manual.
> Isn't there a setting for this in the BIOS setup program?

The Asus Z270E motherboard that I am using has two M.2 slots:

(1) A slot that is NVMe only, but which can be switched in the BIOS between operating at 2x speed or 4x speed. If the latter speed is selected, the extra bandwidth needed is stolen from two of the SATA ports, which then become disabled (SATA ports 5 and 6).

(2) A slot that is switchable in the BIOS between NVMe at 4x speed, or SATA3 (which operates at 6 Gb/s). There is also an AUTO setting in the BIOS whereby the motherboard will detect the capability of the M.2 drive and select the appropriate mode. If the disk is SATA, it disables one of the SATA ports (SATA port 1). I think that the Intel Z270 chipset has a maximum of 6 SATA ports, so if one is used for the M.2 socket, one of the other SATA ports must be disabled.

From the preceding posts, it seems that if you use BIBM as your boot manager (i.e. legacy mode with MBR/EMBR), NVMe disks will be operated at SATA3 speeds (6 Gb/s, i.e. 750 MB/s). If you want to use NVMe disks at NVMe speeds, you will need to use BIU as your boot manager (i.e. UEFI mode with GPT).

You should read the manual for your motherboard carefully, as the capabilities of your board may be different from the capabilities of my Z270E.

-- from CyberSimian in the UK

[Brian K]

My Gigabyte B360M MB only has 1 M.2 socket. It doesn't share any lanes when used in PCIe mode. All 6 SATA ports are available.

I have a second Samsung NVMe PCIe SSD in a M.2 to PCIe adapter card in a PCIe x4 slot.

Both NVMe SSDs work at full speed.

[Bob Coleman]

Brian K wrote:

> BIU can do everything that BIBM does with regard to booting multiple operating
> systems.

I have no doubt that's "true", but I think it's relatively well established that it may not be true on some systems apparently due to UEFI firmware shortcomings. This is probably more prevalent on older systems and/or "budget" systems.

As I think you know, I've made a good faith effort to convert my system (back) to UEFI/GPT and BIU just isn't going to be reliable on this particular system. I don't want to discourage anyone from using or trying to use BIU on a system, but want to insert a note of caution that it may not behave satisfactorily in all cases.

[Brian K]

Bob, I recall your issue. The BIOS kept moving Windows Boot Manager ahead of BootIt UEFI in the Boot Priority order.

[Bob Coleman]

Brian,

Yes and you reproduced the behavior on some system, I think.

[Brian K]

Bob, I did too. It was a computer with a 6 year old MB. A B85M chipset. I persevered and kept changing the Boot Order and after a few days the issue disappeared. All OK with BIU now except Image for UEFI in BIU won't open with Secure Boot enabled and a USB mouse doesn't work. A PS-2 mouse does work.

With my B360M MB, all aspects of BIU work. Secure Boot OK. USB mouse OK.