Toshiba Tecra M11 looking to pay to add Quad core CPU

[DeathBringer]

Have question, if bios does not have information about CPU - will system start? If start - how it will look like?

All(!) BIOS with support of Arrandale core have support of i7-720QM and i7-820QM.
But they can't start in most cases because of laptop's motherboard design.

Power difference we are talking about only 10W.

No, about 20W. Check CPU tab of CPU-Z - your i7-620M has 25W only (with disabled integrated graphics).
So VCC_CORE lines are designed for 25W and VCC_iGFX line are designed for 10W.

Because there is Tecra from same series which used only integrated GFX.

This revision of motherboard can't boot CPUs without integrated graphics.

From power side - there is plenty capacity still available - because full options include 3G modems, PCMCI extensions, and e.t.c.

You need to find a electronic schematics of this motherboard for checking "capacity" of VRM for VCC lines.

From other side i'm 200% sure that there is no mentioned or "supported" in BIOS for 45W CPU and 16GB memory support.

CPUs with Arrandale core support 8GB (4+4) only.
CPUs with Clarksfield core support up to 32GB (8GBx4).