UEFI BIOS Option

[Rockit]

I have two options (CSM) or (UEFI) in my Toshiba Laptop BIOS. When I select UEFI the computer will not boot. I tried to get Toshiba's tech support to explain this to me but besides not speaking english I did not get a clear answer.

If anyone has the time and knowledge to explain this option and it's uses in simple terms I would greatly appreciate it.

Thank You

 

[TVeblen]

When CSM (Compatibility Support Module) is enabled it allows a modern EFI based PC to operate in a Legacy BIOS mode.

This allows for your operating system to be installed and run from a traditional MBR (Master Boot Record) disk and the advanced features of the EFI system are disabled.

Switching to UEFI mode enables the EFI system. UEFI PCs usually use the GPT file table, which includes a hidden SYSTEM partition and a Windows SYSTEM RESERVED partition.

I am assuming that what you meant to say is that with UEFI enabled Windows will not start, not that the PC will not boot. (If the PC did not boot you could not get into the BIOS settings to change it back.)

I believe that this is because Windows was installed in legacy BIOS mode. I believe that to run in UEFI mode you would need to reinstall Windows or make some alterations to the startup process. I do not know if Startup Repair would help in this case. Perhaps someone else here will know this and comment.

These systems are relatively new. I do not own one yet, so I have not had the opportunity to play with one to get hands on experience. What I know is what I've read.

 

[Rockit]

Thank You!

It is a Laptop. And it took awhile before I even found out about that setting.

You are correct .. I get a "no bootable device" message when trying to change it.

I plan on putting in a SSD soon but I was not planning a clean install. I just did that to get rid of the bloatware.

So .. as far as I know .. it's ment for a 3 Terabyte hard drive and the GPT table. The SSD I plan on using is 128 Gig.

Thanks again !!

 

[TVeblen]

Just one small correction to keep the info straight for everyone.

You need to format a disk GPT to use a partition greater than 2.2TB this is true, but you can format a drive of any size GPT.
Not that you would want to or need to with the SSD, just that you could.

My daughter's laptop has a 750GB HDD that is formatted GPT and uses a hybrid UEFI Bios.

 

[Rockit]

Thanks Again,

So .. If I format the SSD to GPT and enable it in the bios. I am guessing I would not be able to clone the current 750 Gig Hd to the SSD but would have to do a clean windows 7 install?

If so would I also need to format the 2nd 1 terabyte Hd to GPT?

Then the UEFI would be enabled and I would gain what?

I'm guessing a GUI interface to access the bios?

Thanks for the replys. I am starting to understand this now, I think.

Here is a link to the laptop -> Toshiba Qosmio X875-Q7290

 

[Cr00zng]

Just the information that I was looking for with my new motherboard, thanks TVeblen...

 

[TVeblen]

Thanks Again,

So .. If I format the SSD to GPT and enable it in the bios. I am guessing I would not be able to clone the current 750 Gig Hd to the SSD but would have to do a clean windows 7 install?

If so would I also need to format the 2nd 1 terabyte Hd to GPT?

Then the UEFI would be enabled and I would gain what?

I'm guessing a GUI interface to access the bios?

Thanks for the replys. I am starting to understand this now, I think.

Here is a link to the laptop -> Toshiba Qosmio X875-Q7290

No, not all correct.

From what I understand, if the BIOS is set to UEFI mode and then you install Windows 7 the installer will do all the hard work. It will set up the GPT, create the needed partitions, and install Windows.

I am not sure if you can alter an existing legacy BIOS installation to work on a UEFI BIOS, I don't have that experience. But I'm pretty sure cloning would be a no.

You do not need to create GPT on any other data drives. That is only necessary if you want partitions that are larger than 2.2TB. The extra drives can be MBR and work fine alongside the GPT disk and vice-versa.

Note that any and all partitions created will still be formated NTFS. That does not change.

UEFI will be enabled only by doing so in BIOS Settings. You do not gain anything immediately by doing so. It is probably not worth the effort if the laptop is all set up. If I can dig up an article explaining the benefits of a UEFI system I will do so (no time now). The GUI interface is not automatic. That has to be set up by the manufacturer. Most laptops use a hybrid BIOS - a UEFI platform but a legacy BIOS interface. I don't know if this can be changed or upgraded.

But if it's a new laptop I would not go changing things just yet. I would only make that change to gain something tangible.

Are we having fun yet?

 

[Britton30]

I'm probably confusing things here, I have a board that only has UEFI available, no legacy BIOS. It is a really nice GUI where you can navigate with the mouse and keyboard. UEFI is also supposed to be more secure against threats infecting the board, I think.
Most UEFI systems allow the user to take a screenshot of the display with a USB drive attached by pressing F12 too.

My drives, SSD for OS, HDD for AppData and Users, are bot MBR partitions.

 

[TVeblen]

Thanks for that Britton.

Some other benefits:

• UEFI BIOS boots faster.
• Allows the native use of the GUID Partition Table (GPT)
• Allows for the use of device drivers at the BIOS level - so you can use a mouse in BIOS GUI for instance
• Allows for support of more processor platforms.

Some good reading:
UEFI - About UEFI
Understanding Disk Partitions
Unified Extensible Firmware Interface - Wikipedia, the free encyclopedia
Installing Windows on UEFI-based Computers


Enjoy!

 

[Cr00zng]

This might be just adding to the confusion...


The Gigabyte GA-Z77X-UP5 TH motherboard in my system has three options regarding to CMOS/BIOS boot:

1. Legacy BIOS only
2. UEFI first and then legacy BIOS
3. UEFI only

The default setting is #2 and works just fine with the SSD drive (Windows 7 OS) that has BIOS based partitioning, or MBR. Changing the the default to #3 prevents Windows from starting, it displays the "Insert or select bootable device..." error message. Presumably, Windows wouldn't have a problem with starting if the default changed to #1.
Evidently, the default setting is the best for quick booting and allows starting up Windows...

 

[TVeblen]

It shouldn't be that confusing. #2 is the Hybrid BIOS. It allows quick booting (as you point out) and then switches over to the normal (legacy) BIOS. So either #1 and #2 will work for your standard Windows installation.

#3 is pure UEFI, and the hard disk must be set up GPT with the EFI System Partition (ESP) or the system cannot find or use the drive.

 

[Cr00zng]

I wasn't really confused...

Based on what I've seen so far, selecting UEFI only requires GPT based partitioning for booting Windows. This has been confirmed in my system where Windows with MBR would not boot when UEFI only selected.

Other post in this thread seems to suggest that having UEFI only allows booting Windows on MBR partition.

Hence the reason for the "confusing" reference in my previous post...

 

[Rockit]

I was told the UEFI option is needed on my laptop by their tech support for a firmware upgrade to the motherboard if I wanted to upgrade the memory.

It would be interesting to try it and see if it gives more options to overclock this laptop.

If you search on youtube for "Asus UEFI" You will see some of the graphical settings being adjusted in windows.

This is going to get very interesting.

 

[Britton30]

I'm confused, lol. This has brought up many questions in my mind. I think my drives are MBR and I installed w7 with no special partitions nor consideration of BIOS and UEFI. I really don't know how to tell what my partitions are, they say Simple/Primary/Basic. The Toshiba here is only storage and is not included in the OS.

 

[essenbe]

If it helps, these are my options in my BIOS. I'm sure there's a lot more than the explain here, but...

 

[Rockit]

I'm confused, lol. This has brought up many questions in my mind. I think my drives are MBR and I installed w7 with no special partitions nor consideration of BIOS and UEFI. I really don't know how to tell what my partitions are, they say Simple/Primary/Basic. The Toshiba here is only storage and is not included in the OS.

View attachment 242840

Where is the recovery partition on your windows 7 install?

 

[Rockit]

If it helps, these are my options in my BIOS. I'm sure there's a lot more than the explain here, but...

View attachment 242842

Do you run that in Windows or do you have to hit a certain key on your keyboard when you startup your computer?

 

[essenbe]

I'm not sure what you mean. It is a picture of my BIOS. On the newer motherboards it will take a picture of any screen in BIOS, by pushing F12, if a USB drive is connected.

 

[TVeblen]

Hey Guys.
Essenbe is a lucky dog that has a motherboard with UEFI BIOS that the manufacturer included the beautiful GUI BIOS Settings.

My daughter's Asus laptop, and a few others I have seen, with a UEFI bios, has BIOS Settings that look just like legacy BIOS settings. No pretty screens, no mouse, just black and blue and white.

So there is no special key to get what Essenbe has, and it is definitely not Windows. That is what he gets when he turns on his computer. We get that old stuff. It's like I said: up to the manufacturer.

If anyone reading this has a LAPTOP with a GUI BIOS, one you can use a mouse in, please let us know. I have not seen one....yet. Just on desktop boards.

 

[TVeblen]

I'm confused, lol. This has brought up many questions in my mind. I think my drives are MBR and I installed w7 with no special partitions nor consideration of BIOS and UEFI. I really don't know how to tell what my partitions are, they say Simple/Primary/Basic. The Toshiba here is only storage and is not included in the OS.

Hey Gary, check out this EXCELLENT tutorial here :
http://www.sevenforums.com/tutorials/244566-hard-drive-gpt-mbr.html