Max resolution for external monitor, while laptop panel on?

[tudsy]

Hi,
I have a straightforward question I can't find an answer to. I'm getting a new T400 (1440x900 CCFL) with the intel 4500MHD chipset and want to set up a dual monitor situation where
1. The 1440x900 CCFL panel of the laptop is one monitor
2. Second monitor connected via VGA port (no dockstation)
3. I want the two monitors to operate in 'Extended Desktop Mode', i.e., different windows on different monitors, single window spanning the monitors, etc.

???: What is the maximum supported and/or recommended resolution for the external display? Hopefully at least 1680x1050, ideally 1920x1080...

Also, if there's some major advantage to using the dockstation in this regard, feel free to inform.
Thanks!

[dr_st]

2048x1536 is the maximum VGA resolution.

The advantage of using a docking station (if it is the mini-dock at least) is that you can connect LCD monitors via DVI, which is sharper at higher resolutions.

[tudsy]

Thanks.
2048 x 1536 can be supported over the VGA at the same time as the 1440x900 of the laptop panel?

And that's for extended desktop mode, not for the same thing on both displays?
Agreed that high resolution on VGA isn't great.

[dr_st]

Yes, and yes, for extended desktop only.