ThinkPad T520 Optimus 4 displays under XP

[Mike350]

Hi,

I have a new ThinkPad T520 with Optimus technology, along with a Mini Dock Plus Series 3. With this setup you can run up to 4 displays (3 external plus the internal LCD) using the built-in Intel and NVIDIA graphics.

The problem is that while this works fine under Windows 7, our organization uses Windows XP, and I cannot get both display adapters to work independently under XP. This is disappointing since this unit is replacing an R60 with a full dock, where I was able to run 4 displays under XP using a video card in the dock along with the integrated graphics in the R60.

Note that I don't care about the Optimus graphics *switching*, all I want is for both display adapters to function under XP so I can run 4 displays with the system in the dock. Has anybody managed to make this work?

Thanks,
Mike

[Colonel O'Neill]

80% sure it won't work. It's an Optimus specific feature. Something about framebuffers.

[Mike350]

It's a shame that Lenovo won't provide XP drivers for the graphics to run as 2 separate video cards. I can get the Intel to work but not the NVidia with the bios set to optimus. Although to get the Intel to work under XP I have to force the drivers as the hardware ID is not in the driver.

[Colonel O'Neill]

It's not a Lenovo issue; NVidia never intended for Optimus to function with XP as XP doesn't take to multiple display adapters and outputs well (SLI and Crossfire notwithstanding).

[Mike350]

XP actually supports multiple video adapters quite well, far better than Vista for example. XP supports heterogeneous video displays, while vista only supported homogeneous adapters. MS finally corrected that flaw in Win7, bringing back the heterogeneous support that XP had all along. XP sees both adapters, it is only for the lack of a driver that both cannot be used.

[Colonel O'Neill]

Ah; I missed the part of running them seperately. Someone on the Lenovo forum claims to have had it working as you wanted on an ATI/Intel switchable system, although was unsupported and eventually broke. I think that was Windows 7 instead of XP too, although it was apparently not intended for the ATI/Intel switchable system to drive a total of three monitors.

Maybe it's possible to just forcibly install non-Optimus NVidia drivers for the 3100M manually, and install non-Optimus Intel drivers for the IGP manually.

[ryan1212]

Hopefully your group upgrades to Windows 7 soon! XP is 10 years old come August, I would not expect new hardware to even support it.