What is UEFI and when was it introduced on Lenovo systems?
What is UEFI?
- UEFI is a replacement for 16-bit legacy BIOS that has been in use since the 1990s
- As 64-bit code, it solves many of the limitations of 16-bit legacy BIOS, including max 2TB boot disks, option ROM conflicts, and it will also (eventually) provide for a faster, richer preboot experience
- UEFI BIOS is still stored onboard, in ROM chips (just like legacy BIOS). The methods to update UEFI BIOS are no different than legacy BIOS (from end user perspective).
- The transition from legacy BIOS to UEFI BIOS is similar to the transition from 16-bit OS to 32-bit OS (or 32-bit to 64-bit). There will be a period of time where, for compatibility reasons, UEFI BIOS has to emulate legacy BIOS so that existing applications aren't broken. Lenovo is committed to providing legacy support in UEFI until around 2014 when Windows XP finally goes end-of-life.
What is GPT?
- GUID Partition Table, the replacement for Master Boot Record (MBR).
- Where legacy BIOS boots to MBR, UEFI BIOS boots to GPT. UEFI cannot boot MBR, and legacy BIOS cannot boot GPT.
When is Lenovo introducing UEFI?
- Lenovo introduced UEFI with the Hurron River chipset equipped ThinkPads (e.g. any of the new 2011 models, including Edge) (X220, T420, T420s, T520, W520, Edge E220s, E420s, etc)
- In BIOS F1 setup, there are options to turn it on or off:
UEFI/Legacy Boot: default is both, other options are legacy-only and UEFI-only
UEFI/Legacy Boot Priority: default is legacy, other option is UEFI
- All of today's preloads are based on MBR which means legacy boot.
1. Will a UEFI BIOS ever be released for systems prior to Huron River (e.g. T410/X201/W510/etc)? No
2. Can I change my BIOS option to UEFI only? No, because your preloaded system will no longer boot (it is based on MBR which requires legacy boot)
3. Can I change my BIOS option to UEFI only and then run factory recovery? No, because today's factory recovery only knows how to create the MBR-based installation of Windows 7 that requires legacy boot.
4. Will GPT-based recovery disks ever be released for the T420/T520/X220/W520 system that I already own? No
5. Can I change my BIOS option to UEFI only and then install Windows 7 64-bit from scratch myself, without using recovery disks? Yes, but there are some known issues:
a. bitlocker won't work (BIOS fix coming in July/August)
b. fingerprint software won't work (new software release coming in July/August)
c. on W520, you can't install Win7 on a hardware RAID volume (BIOS fix TBD)
d. Rescue and Recovery won't work (new software release coming in July/August)
e. 3rd-party full-disk encryption software won't work (e.g. Sophos SafeGuard, WinMagic SecureDoc, McAfee EEPC etc). We are working with those companies on UEFI support but I think that will go well into 2012
6. Will UEFI make my system POST faster? Eventually, but not today, due to the fact that many legacy BIOS features are still emulated for compatibility reasons (even in UEFI mode). All of the great EE 2.0 claims that you see about booting fast on T420s and other systems? That's actually all being done in legacy BIOS! The CES demos were done on a special/prototype UEFI BIOS that drops legacy support (which is not something we can currently ship).
7. Will UEFI make Windows/games/benchmarks run faster? No
8. Will UEFI make my fan run slower/quieter? No
9. When will Lenovo ship systems with a GPT-based preload? Those plans are still being made, but there will probably be some UEFI/GPT preloads in Ivy Bridge products in 2012 (e.g. T530/W530/etc).
10. How do I know if I have a GPT installation of Windows 7? You will have an EFI system partition at the beginning of the HDD. See http://technet.microsoft.com/en-us/library/dd74430