CentOS - Oct 2012 - CentOS 6 - Does EFI have an impact beyond the boot sequence?

Hello,

I am using an up to date CentOS 6 x86_64 laptop (Thinkpad X220t) and
after struggling a bit I could install it a few months ago with a pure
EFI boot.

However, I am not really satisfied with such things as stability,
power consumption, etc. and now that I have a little more time I want
to investigate these issues thoroughly.

So, my questions are:

- Does EFI impacts other things than the boot sequence? (a friend of
mine told me that this is a complete replacement of BIOS, and thus
impacts "everything")

- Could it change (improve?) stability, power consumption, etc. if I
would reinstall CentOS 6 using the traditional boot? (or is it just a
legacy wrapper around an EFI "BIOS"?)

Thanks in advance for your advice or for providing more details about
what you know about EFI pro and cons!

Cheers,

Mathieu

On 15.10.2012 09:31, Mathieu Baudier wrote:
> Hello,
>
> I am using an up to date CentOS 6 x86_64 laptop (Thinkpad X220t) and
> after struggling a bit I could install it a few months ago with a 
> pure
> EFI boot.
>
> However, I am not really satisfied with such things as stability,
> power consumption, etc. and now that I have a little more time I want
> to investigate these issues thoroughly.
>
> So, my questions are:
>
> - Does EFI impacts other things than the boot sequence? (a friend of
> mine told me that this is a complete replacement of BIOS, and thus
> impacts "everything")
>
> - Could it change (improve?) stability, power consumption, etc. if I
> would reinstall CentOS 6 using the traditional boot? (or is it just a
> legacy wrapper around an EFI "BIOS"?)
>
> Thanks in advance for your advice or for providing more details about
> what you know about EFI pro and cons!
Hello Mathieu,

Not sure about the EFI as I'm avoiding it as the plague, but on Intel 
platforms there are some issues regarding power consumption. Here's what 
I do:
http://www.nux.ro/archive/2012/10/EL6_power_usage_optimisation_on_Intel_Sandy___Ivy_Bridge.html

-- 
Sent from the Delta quadrant using Borg technology!

Nux!
www.nux.ro

Hi,

On 10/15/2012 09:31 AM, Mathieu Baudier wrote:
> I am using an up to date CentOS 6 x86_64 laptop (Thinkpad X220t) and
> after struggling a bit I could install it a few months ago with a pure
> EFI boot.
Are you sure it wasent doing a bios failback ? I'd be surprised to see a
device like that with exclusive uEFI support ( although, I know lots of
people run CentOS 6 on MacBook Air's and Macbook's of various shapes /
sizes, which have no bios mode )
> So, my questions are:
> 
> - Does EFI impacts other things than the boot sequence? (a friend of
> mine told me that this is a complete replacement of BIOS, and thus
> impacts "everything")
to some extent yes, but once the machine is running and dmi stuff has
been setup, there would be little impact
> - Could it change (improve?) stability, power consumption, etc. if I
> would reinstall CentOS 6 using the traditional boot? (or is it just a
> legacy wrapper around an EFI "BIOS"?)
its the same grub, running with different paths. There should be no
stability impact as far as I can tell.
> Thanks in advance for your advice or for providing more details about
> what you know about EFI pro and cons!
I've switched over everything that is capable of running uEFI to uEFI
modes ( including my HP EliteBook laptop ) - and dont have any stability
or performance issues ( that I've noticed anyway ).

-- 
Karanbir Singh
+44-207-0999389 | http://www.karan.org/ | twitter.com/kbsingh
ICQ: 2522219    | Yahoo IM: z00dax      | Gtalk: z00dax
GnuPG Key : http://www.karan.org/publickey.asc

On 10/15/2012 01:31 AM, Mathieu Baudier wrote:
> - Does EFI impacts other things than the boot sequence? (a friend of
> mine told me that this is a complete replacement of BIOS, and thus
> impacts "everything")
EFI will primarily impact driver initialization.  If you saw a problem, 
it would be during the kernel startup, before the init process began, or 
during suspend and resume.  It shouldn't impact power use or stability 
in general.
> - Could it change (improve?) stability, power consumption, etc. if I
> would reinstall CentOS 6 using the traditional boot? (or is it just a
> legacy wrapper around an EFI "BIOS"?)
The EFI firmware provides a legacy BIOS wrapper.