As reported in german newsgroup, customers are not happy with the behaviour of "swichable Graphics" during boot-procedure.
With T410s (and probably some other models) with Switchable Graphics the external Monitor, connected to the Mini-Dock, stays black while booting. This is a BIG problem, if you have configured a Power-On-Password: You don't see any password-prompt, and no confirmation message whether your (blind) typed password is accepted. You must be pationt and pray or open your notebook-display. Here we do not use the Fingerprint-readers, because we don't want to open the display - just dock in and start.
The "bad" Solution:
Display->Graphics Device [Discrete Graphics]
Display->OS Detection for Switchable Graphics [Disabled]
With this Solution, actually the only possibility, there are NO SWITCHABLE GRAPHICS available any more, you will always use the (battery expensive) "Discrete Graphics".
If I Set
Display->OS Detection for Switchable Graphics [Enabled], the System (Graphics Driver ? Windows 7?) will CHANGE my BIOS-Setting from
Display->Graphics Device [Discrete Graphics] to Display->Graphics Device [Switchable Graphics]. Then, after booting UNDOCKED, the next boot DOCKED will cause the same problem again: as actual graphics devise is used Integrated Graphics, which does not support any external Monitors on the mini-Dock, my external Monitor stays black.
The "better" Solution should come from Lenovo:
For example an additional BIOS-Setting
"Graphics Device for Boot procedure", which cannot be affected by the OS/Graphics Driver.
Or just to forbid the System to change the BIOS-Setting for "Display->Graphics Device". The System should be allowed to switch graphics if "Display->OS Detection for Switchable Graphics" is set to [Enabled], but without changing the BIOS-Setting
Please, Mr. Lenovo, this can not be so complicated.