T400 with dual graphics, 3 monitors at once - WORKING!

[kitor]

I have T400 with dual (intel + ATI) graphics cards. Running on Windows 8 (using Win7 driver). Everything's connected to Advanced MiniDock.
I've read about possibility of running three-four monitors at once on T500 (here's LINK), and I'm almost sure that I've seen something similar about T400 on this forums.

Anyway, after replacing ATI driver with official one for Win8, and Intel with system one - I can see, even enable three-four displays at once (Intel has access to VGA and internal LCD, ATI to VGA, internal LCD and DVI), but the problem is that monitors driven by Intel graphics has no output at all. In theory setup like
ATI or Intel for internal LCD, ATI for DVI and Intel for VGA should work, and this can be set up from windows display applet.
Card is rendering - as I can take screenshot of whole desktop, move windows between monitors when having setup like ATI-Intel-ATI, etc - seems that some hardware multiplexer (?) is just forcing all outputs to be connected to ATI card.

Anyone had experience with this before and can help me?
If you gonna write that "it's impossible, thinkpads can do only two displays at once", please just leave this alone

[craigmontHunter]

Unfortunately, it is impossible to drive 4 displays at once off the T400. While there appear to be 4 display options on the system, they are the same "connection" - there is a single digital and a single analog video pathway, and the video cards switch entirely - you cannot have both of them enabled at the same time, so there is a maximum of 2 displays running at any one time (internal + external or 2 externals) (source, my brother has a t400 with switchable graphics, and I have spent a fair bit of time playing with it).

That is not true of later ThinkPads with optimus gpus - since they essentially run the dedicated GPU "Through" the integrated one, you can drive up to 4 displays off the system (as seen here )

EDIT: I finally looked at the link you included, and there are instructions listed on the second page, which seem to require that you don't install the switchable driver, just the ATI driver on a clean install - YMMV, but if you could get it to work, please post the relevant info, since this seems really neat. I don't know how it performs or how stable it is, and I'd imagine it would be brutal on battery life to have both GPUs running at the same time all the time - without the switchable driver there isn't a clean way to turn the dedicated one off.

I think your best chance at success would be a clean install on a spare drive, then follow the directions given in post 14 on that link.

[kitor]

I got it working on Windows 7. Using drivers:
"VGA_Intel_WIN7_64_815101872.zip" for Intel card, and
"9-9_vista64_win7_64_dd_ccc_wdm_enu.exe" for ATI one.
I needed to use Mobility Modder.NET on ATI driver to make it support mobile card.

After that I got three displays working (sorry, don't have spare monitor to try on 4 displays). Internal LCD and VGA out are driven by GMA, and DVI is on ATI card.

Proof:
Photo of desktop: LINK(350kb)
Video of working setup: LINK (youtube)

Both external monitors are connected to docking station. I'll try to disable internal LCD and connect third external one to thinkpad's internal analog output. If this will work - this will be the best laptop I ever have

I need to test this driver configuration under Windows 8.
About battery and so on - Windows has support for "hardware profiles", so maybe there's a way to mess a bit with it and use different drivers for docked and undocked state.

[e]
Ouch, there seems to be no support for hardware profiles in newer windows versions, or I'm missing something
Third external display will not work - internal VGA is connected to ATI card and there's no output. On T500 third external display is possible using DisplayPort (HDMI?), cause as it's digital - it's connected to ATI only.

[shrds4m3]

Almost have this now as well. I am running Windows 8.1 Pro and with too much time spent, this is what Ive got:

Only issue is that when the laptop goes on the dock the LCD does not turn on w/ the monitors (despite the control panel saying it is)
I know I just need to find a way to turn on the LCD as I used Skype to look at the desktop (if driver recommendations are out Ill take)
(Using GMA4500MHD + ATI/AMD Radeon HD 3400)

since i cant take a picture for now Ill just type the monitor lay out
(3)Syncmaster-ATi Radeon 3400[driver Windows 8.1 Beta] (1)ThinkPad Display- GMA4500MHD[Intel4S.E.C.F (WDDM1.1)] (4)ATi RadeonHD3400[driver Windows 8.1 Beta] (2)ThinkPad Display-Disconnected

The Intel Driver I am using is the standard WDDM
The AMD is Radeon 3400 Windows 8 Beta :http://support.amd.com/en-us/download/d ... 8%20-%2064
(edit) so I have updated intel to OpenGL :http://h10025.www1.hp.com/ewfrf/wc/soft ... ob-63811-1
Wish me luck ShardsForme